Transfers and Servicing [Abstract] Mortgage Servicing Rights (MSRs) and Related Liabilities Transfers and Servicing of Financial Assets [Text Block] Reverse Mortgage Interests [Abstract] Reverse Mortgage Interests [Abstract] Mortgage Servicing Rights [Table] Mortgage Servicing Rights [Table] Mortgage Servicing Rights [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Mortgage-backed debt Mortgages [Member] Mortgage Servicing Rights [Line Items] Mortgage Servicing Rights [Line Items] Mortgage Servicing Rights [Line Items] Participating interests in HECM mortgage-backed securities (“HMBS”), net of $36 and $58 premium, respectively Reverse Mortgage Interest Subject to Non-Recourse Debt Reverse Mortgage Interest Subject to Non-Recourse Debt Other interests securitized, net of $112 and $100 discount, respectively Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized Unsecuritized interests, net of $95 and $122 discount, respectively Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized Reserves Reverse Funded Loan Advances, Reserves Reverse Funded Loan Advances, Reserves Total reverse mortgage interests, net Reverse Funded Loan Advances Reverse funded loan advances Debt premium Debt Instrument, Unamortized Premium Other interests securitized, discount Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount Unsecuritized interests, discount Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships Customer Relationships [Member] Tradename Trade Names [Member] Technology Technology-Based Intangible Assets [Member] Internally developed software Software Development [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Pacific Union Pacific Union Financial, LLC [Member] Pacific Union Financial, LLC [Member] Nationstar Mortgage Holdings Inc. Nationstar Mortgage Holdings Inc. [Member] Nationstar Mortgage Holdings Inc. [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Preliminary Estimated Fair Value of Net Assets Acquired: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Assets: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Restricted cash Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Restricted Cash And Equivalents Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Restricted Cash And Equivalents Mortgage servicing rights Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Rights Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Rights Advances and other receivables Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advances And Other Receivables Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advances And Other Receivables Reverse mortgage interests Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Reverse Mortgage Interests Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Reverse Mortgage Interests Mortgage loans held for sale Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Loans Held For Sale Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Loans Held For Sale Mortgage loans held for investment Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Loans Held For Investment Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Loans Held For Investment Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Other assets Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Assets Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Assets Fair value of assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Liabilities: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Notes payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Unsecured senior notes Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Unsecured Debt Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Unsecured Debt Advance facilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advance Facilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Advance Facilities Warehouse facilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Warehouse Facilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Warehouse Facilities Payables and other liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accounts Payable And Accrued Liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accounts Payable And Accrued Liabilities MSR related liabilities—nonrecourse Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Liabilities, Nonrecourse Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Liabilities, Nonrecourse Mortgage servicing liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Liabilities Other nonrecourse debt Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Nonrecourse Debt Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Nonrecourse Debt Fair value of liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Total fair value of net tangible assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Preliminary goodwill Goodwill Total Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Useful Life, Assets acquired Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Mortgage Loans Held for Sale and Investment [Abstract] Mortgage Loans Held for Sale and Investment Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Predecessor Predecessor [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward] Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward] Balance - beginning of period Loans Receivable Held-for-sale, Amount Mortgage loans originated and purchased, net of fees Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Additions to Held-for-sale Loans sold Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Deductions from Held-for-sale Repurchase of loans out of Ginnie Mae securitizations Repurchase of Ginnie Mae Receivables Repurchase of Ginnie Mae Receivables Transfer of mortgage loans held for sale to advances/accounts receivable, net related to claims Claims Made to Third Parties Claims Made to Third Parties Net transfer of mortgage loans held for sale from REO in other assets Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Transfer from Held-for-sale to Held For Investment or Other Assets Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Transfer from Held-for-sale to Held For Investment or Other Assets Changes in fair value Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Changes in Fair Value Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Changes in Fair Value Other purchase-related activities Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Other Loans Receivable Held-for-sale, Reconciliation to Cash Flow, Other Balance - end of period Leases [Abstract] Lease costs Lease, Cost [Table Text Block] Lease Maturity, Operating Lessee, Operating Lease, Liability, Maturity [Table Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Current Reporting Status Entity Current Reporting Status Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Condensed Financial Information Disclosure [Abstract] Condensed Financial Statements [Table] Condensed Financial Statements [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Mr. Cooper Parent Company [Member] Issuer Subsidiary Issuer [Member] Guarantor (Subsidiaries of Issuer) Guarantor Subsidiaries [Member] Non-Guarantor (Subsidiaries of Issuer) Non-Guarantor Subsidiaries [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Reportable entities Reportable Legal Entities [Member] Eliminations Consolidation, Eliminations [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) attributable to Nationstar Net Income (Loss) Attributable to Parent Adjustments to reconcile net income (loss) to net cash attributable to operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Deferred tax (benefit) expense Deferred Income Tax Expense (Benefit) (Gain) loss from subsidiaries Intercompany Gains (Losses) Intercompany Gains (Losses) Net gain on mortgage loans held for sale Gain (Loss) on Sales of Loans, Net Interest income on reverse mortgage loan Interest Income, Reverse Mortgages Interest Income, Reverse Mortgages (Gain) loss on sale of assets Gain (Loss) on Disposition of Assets Provision for servicing reserves Provision for Reserves on Advance and Other Receivables Provision for Reserves on Advance and Other Receivables Fair value changes and amortization/accretion of mortgage servicing rights/liabilities Mortgage Servicing Rights (MSR) Impairment (Recovery) Fair value changes in excess spread financing Fair Value Changes in Excess Financing Spread Fair value changes in excess spread financing Fair value changes in mortgage servicing rights financing liability Fair Value Changes in MSR Financing Liability Fair Value Changes in mortgage servicing rights financing liability Fair value changes in mortgage loan held for investment Mortgage Loans Held For Investment, Change In Fair Value Mortgage Loans Held For Investment, Change In Fair Value Amortization of premiums, net of discount accretion Accretion (Amortization) of Discounts and Premiums, Investments Depreciation and amortization for property and equipment and intangible assets Depreciation, Depletion and Amortization Share-based compensation Share-based Compensation Repurchases of forward loan assets out of Ginnie Mae securitizations Repurchase of Forward Loan Assets out of Ginnie Mae Securitizations Repurchase of Forward Loan Assets out of Ginnie Mae Securitizations Mortgage loans originated and purchased for sale, net of fees Payments for Origination and Purchases of Loans Held-for-sale Sales proceeds and loan payment proceeds for mortgage loans held for sale and held for investment Proceeds From Sale And Other Changes In Mortgage Loan Held For Sale Proceeds from sale and other changes in mortgage loan held for sale. Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Advances and other receivables Increase (Decrease) in Accounts Receivable Reverse mortgage interests Increase Decrease in Reverse Funded Advances Due to Securitization Reverse funded advances due to securitization Other assets Increase (Decrease) in Other Operating Assets Payables and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Net cash attributable to operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Property and equipment additions, net of disposals Payments for (Proceeds from) Productive Assets Purchase of forward mortgage servicing rights, net of liabilities incurred Payments (Proceeds) To Acquire Mortgage Servicing Rights (MSR) Payments (Proceeds) To Acquire Mortgage Servicing Rights (MSR) Net proceeds from acquisition of reverse mortgage servicing portfolio and HECM related receivables Proceeds (Payments) From Acquisition Of Reverse Mortgage Interests And Home Equity Conversion Mortgage Related Receivables Proceeds (Payments) From Acquisition Of Reverse Mortgage Interests And Home Equity Conversion Mortgage Related Receivables Proceeds on sale of forward and reverse mortgage servicing rights Proceeds (Repayments) From Sale Of Mortgage Servicing Rights (MSR) Proceeds (Repayments) From Sale Of Mortgage Servicing Rights (MSR) Proceeds on sale of assets Proceeds from Sale of Productive Assets Net cash attributable to investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Increase (decrease) in warehouse facilities Proceeds from (Repayments of) Secured Debt Increase (decrease) in advance facilities Proceeds from (Repayments of) Lines of Credit Repayment of notes payable Proceeds from (Repayments of) Notes Payable Proceeds from issuance of HECM securitizations Proceeds from Other Debt Proceeds from sale of HECM securitizations Proceeds From Sale Of Home Equity Conversion Mortgages Proceeds From Sale Of Home Equity Conversion Mortgages Repayment of HECM securitizations Repayments of Other Debt Proceeds from issuance of participating interest financing in reverse mortgage interests, net Proceeds From Issuance Of Participating Interest Financing In Reverse Mortgage Interests, Net Proceeds From Issuance Of Participating Interest Financing In Reverse Mortgage Interests, Net Repayment of participating interest financing in reverse mortgage interests Proceeds from (Payments for) Mortgage Backed Securities Notes Payable Proceeds from (Payments for) Mortgage Backed Securities Notes Payable Proceeds from the issuance of excess spread financing Proceeds from Excess Spread Financing Proceeds from Excess Spread Financing Settlement of excess spread financing Payment For Settlement Of Excess Servicing Spread Financing Payment For Settlement Of Excess Servicing Spread Financing Repayment of nonrecourse debt – legacy assets Repayment of Nonrecourse Debt Legacy Assets Repayment of nonrecourse debt - Legacy assets Repayment of finance lease liability Finance Lease, Principal Payments Repurchase of unsecured senior notes Payment for Repurchase of Unsecured Debt Payment for Repurchase of Unsecured Debt Surrender of shares relating to stock vesting Payments Related to Tax Withholding for Share-based Compensation Debt financing costs Payments of Financing Costs Net cash attributable to financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash, cash equivalents, and restricted cash - beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents, and restricted cash - end of period Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Litigation and Regulatory Matters Litigation and Regulatory Matters [Member] Litigation and Regulatory Matters [Member] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Reverse Mortgage Servicing Rights, Excluding Subservicing Reverse Mortgage Servicing Rights, Excluding Subservicing [Member] Reverse Mortgage Servicing Rights, Excluding Subservicing [Member] Warehouse facilities, net of unamortized debt issuance costs Reverse Mortgages [Member] Reverse Mortgages [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Legal fees Legal Fees Estimate of possible loss Loss Contingency, Estimate of Possible Loss UPB Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement Unfunded advance obligations Off-balance Sheet, Maximum Advance Obligation of Reverse Mortgages Serviced Off-balance Sheet, Maximum Advance Obligation of Reverse Mortgages Serviced Segment Reporting [Abstract] Business Segment Reporting Segment Reporting Disclosure [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Basis of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Recent Accounting Guidance Adopted and Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Leases, Finance Lessee, Finance Leases [Text Block] Leases, Operating Lessee, Operating Leases [Text Block] Income Tax Disclosure [Abstract] Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] (Loss) income before income tax expense (benefit) Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax (benefit) expense Income Tax Expense (Benefit) Effective tax rate Effective Income Tax Rate Reconciliation, Percent Statutory federal rate percentage Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Reverse Mortgage Interest [Abstract] Reverse Mortgage Interest [Abstract] Repurchased HECM loans (exceeds 98% MCA) Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Repurchase of Home Equity Conversion Mortgages Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Repurchase of Home Equity Conversion Mortgages HECM related receivables Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Home Equity Conversion Mortgage Receivables Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Home Equity Conversion Mortgage Receivables Funded borrower draws not yet securitized Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Funded Draws Not Yet Securitized Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Funded Draws Not Yet Securitized REO-related receivables Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Real Estate Owned Related Receivables Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Real Estate Owned Related Receivables Purchase discount Total unsecuritized interests Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Schedule of Other Assets Schedule of Other Assets [Table Text Block] Schedule of Goodwill Schedule of Goodwill [Table Text Block] Reverse Mortgage Interests, Net Reverse Mortgage Interest Disclosure [Text Block] Reverse Mortgage Interest Disclosure [Text Block] Schedule of Segment Reporting Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Servicing Segment Servicing Segment [Member] Servicing Segment [Member] Originations Segment Originations Segment [Member] Originations Segment [Member] Notes Payable, Other Notes Payable, Other Payables [Member] Advance facilities Advance Facilities [Member] Advance Facilities [Member] Notes Payable to Banks Notes Payable to Banks [Member] Mortgage servicing rights Mortgage Servicing Right [Member] Mortgage Servicing Right [Member] Warehouse Facilities Warehouse Facilities [Member] Warehouse Facilities [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Nationstar agency advance receivables trust Nationstar Advance Agency Receivables Trust [Member] Nationstar Advance Agency Receivables Trust [Member] Nationstar mortgage advance receivable trust NSM Advance Receivable Trust (2013) [Member] NSM Advance Receivable Trust (2013) [Member] MBS servicer advance facility (2014) MBS Servicer Advance Facility (2014) [Domain] MBS Servicer Advance Facility (2014) [Domain] Nationstar agency advance financing facility Agency Advance Financing Facility (2011) [Member] Agency Advance Financing Facility (2011) [Member] $1,000 warehouse facility $1000 Warehouse Facility Due September 2017 [Member] $1000 Warehouse Facility Due September 2017 [Member] $950 warehouse facility $950 Warehouse Facility [Member] $950 Warehouse Facility [Member] $800 warehouse facility $600 Warehouse Facility Due April 2020 [Member] $600 Warehouse Facility Due April 2020 [Member] $600 warehouse facility $600 Warehouse Facility [Member] $600 Warehouse Facility [Member] $500 warehouse facility $500 Warehouse Facility Due September 2020 [Member] $500 Warehouse Facility Due September 2020 [Member] $500 warehouse facility Warehouse Facility $500 Million [Member] Warehouse Facility $500 Million [Member] $500 warehouse facility $500 Million Warehouse Facility Due April 2019 [Member] $500 Million Warehouse Facility Due April 2019 [Member] $500 warehouse facility $500 Warehouse Facility Due August 2019 [Member] $500 Warehouse Facility Due August 2019 [Member] $250 warehouse facility $250 Warehouse Facility [Member] $250 Warehouse Facility [Member] $200 warehouse facility $200 Warehouse Facility, Due 2020 [Member] $200 Warehouse Facility, Due 2020 [Member] $200 warehouse facility Warehouse Facility $200 Million [Member] Warehouse Facility $200 Million [Member] $200 warehouse facility $200 Warehouse Facility Due April 2021 [Member] $200 Warehouse Facility Due April 2021 [Member] $165 warehouse facility $165 Warehouse Facility Due August 2019 [Member] $165 Warehouse Facility Due August 2019 [Member] $50 warehouse facility $50 Warehouse Facility [Member] $50 Warehouse Facility [Member] $40 warehouse facility $40 million Warehouse Facility [Member] $40 million Warehouse Facility [Member] $200 warehouse facility Mortgage Servicing Right, $200 Warehouse Facility Due April 2020 [Member] Mortgage Servicing Right, $200 Warehouse Facility Due April 2020 [Member] $200 warehouse facility Mortgage Servicing Right, $200 Warehouse Facility Due June 2020 [Member] Mortgage Servicing Right, $200 Warehouse Facility Due June 2020 [Member] $175 warehouse facility Mortgage Servicing Right, $175 Warehouse Facility Due December 2020 [Member] Mortgage Servicing Right, $175 Warehouse Facility Due December 2020 [Member] $50 warehouse facility Mortgage Servicing Right, $50 Warehouse Facility Due August 2020 [Member] Mortgage Servicing Right, $50 Warehouse Facility Due August 2020 [Member] Mortgage loans, net Loans Held-for-sale, Mortgages [Member] Loans Held-for-sale, Mortgages [Member] Reverse mortgage interests MSR Mortgage Servicing Rights and Other Collaterals [Member] Mortgage Servicing Rights and Other Collaterals [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] CPRATE Corporate Rate (CPRATE) [Member] Corporate Rate (CPRATE) [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Capacity Amount Line of Credit Facility, Maximum Borrowing Capacity Debt outstanding, gross Secured Debt, Gross Secured Debt, Gross Debt Outstanding Secured Debt Collateral Pledged Debt Instrument, Collateral Amount Unamortized debt issuance costs Debt Issuance Costs, Net Basis spread on rate Debt Instrument, Basis Spread on Variable Rate Operating cash flows from operating leases Operating Lease, Payments Leased assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Weighted-average remaining lease term - operating leases, in years Operating Lease, Weighted Average Remaining Lease Term Weighted-average discount rate - operating leases Operating Lease, Weighted Average Discount Rate, Percent Fair Value Disclosures [Abstract] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Payables and Accruals [Abstract] Payables and Other Liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Net (loss) income attributable to Successor/Predecessor Adjustments to reconcile net (loss) income to net cash attributable to operating activities: Gain on sale of assets Amortization of premiums, net of discount accretion Share-based compensation Mortgage loans originated and purchased for sale, net of fees Sales proceeds and loan payment proceeds for mortgage loans held for sale and held for investment Advances and other receivables Reverse mortgage interests Payables and other liabilities Property and equipment additions, net of disposals Purchase of forward mortgage servicing rights, net of liabilities incurred Net payment related to acquisition of HECM related receivables Net Payments (Proceeds) Related To Acquisitions Of HECM Related Receivables Net Payments (Proceeds) Related To Acquisitions Of HECM Related Receivables Decrease in advance facilities Proceeds from issuance of participating interest financing in reverse mortgage interests Repayment of participating interest financing in reverse mortgage interests Debt financing costs Supplemental Disclosures of Cash Activities Supplemental Cash Flow Elements [Abstract] Cash paid for interest expense Interest Paid, Including Capitalized Interest, Operating and Investing Activities Net cash paid for income taxes Income Taxes Paid, Net Earnings Per Share [Abstract] Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Preferred Stock Preferred Stock [Member] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Treasury Share Amount Treasury Stock [Member] Total Nationstar Stockholders’ Equity and Mr. Cooper Stockholders’ Equity, respectively Parent [Member] Non-controlling Interests Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning of Period, shares Shares, Outstanding Beginning of Period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Shares issued / (surrendered) under incentive compensation plan, shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Shares issued / (surrendered) under incentive compensation plan Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Ending of Period Ending of Period, shares Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Change in Discount Rate [Axis] Change in Discount Rate [Axis] Change in Discount Rate [Axis] Change in Discount Rate [Domain] Change in Discount Rate [Domain] Change in Discount Rate [Domain] 100 Basis Points One Hundred Basis Points [Member] One Hundred Basis Points [Member] 200 Basis Points Two Hundred Basis Points [Member] Two Hundred Basis Points [Member] Excess spread financing Excess Spread Financing [Member] Excess Spread Financing [Member] Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items] Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items] Discount Rate, Adverse Change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of Other than 10 or 20 Percent Adverse Change in Discount Rate Total Prepayment Speeds, 10% Adverse Change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Prepayment Speed Total Prepayment Speeds, 20% Adverse Change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Adverse Change in Prepayment Speed Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table] Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table] MSR Financing Liability MSR Financing Liability [Member] MSR Financing Liability Servicing Assets and Servicing Liabilities Risk [Axis] Servicing Assets and Servicing Liabilities Risk [Axis] Risks Inherent in Servicing Assets and Servicing Liabilities, Type [Domain] Risks Inherent in Servicing Assets and Servicing Liabilities, Type [Domain] Credit sensitive Credit Risk [Member] Interest sensitive Interest Rate Risk [Member] Low High Weighted-average Weighted Average [Member] Weighted Average Assumption [Axis] Weighted Average Assumption [Axis] Weighted Average Assumption [Axis] Weighted Average Assumption [Domain] Weighted Average Assumption [Domain] [Domain] for Weighted Average Assumption [Axis] Financing rates Financing rates [Member] financing rates Recovery rates Recovery rates [Member] Recovery rates Assumption for Fair Value of Mortgage Servicing Rights Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items] Discount rate Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate Total prepayment speeds Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed Expected weighted-average life Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Expected weighted-average life Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Expected weighted-average life Prepayment Speeds Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Prepayment Speed Average Life (Years) Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Weighted Average Life Discount Rate Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Discount Rate Recapture Rate Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Recapture Rate Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Recapture Rate Advance financing rates Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Advanced Financing Rate Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Advanced Financing Rate Annual advance recovery rates Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Annual Advanced Recovery Rates Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Annual Advanced Recovery Rates Mortgage loans held for investment, net Mortgage Loans Held for Investment [Member] Mortgage Loans Held for Investment [Member] Mortgage loans held for investment, net – UPB Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance Fair value adjustments Mortgage Loans Held For Investment, Fair Value Adjustment Mortgage Loans Held For Investment, Fair Value Adjustment Total mortgage loans held for investment Mortgage Loans Held for Investment Subject to Nonrecourse Debt Legacy Assets Net Mortgage loans held for investment, subject to nonrecourse debt - Legacy Assets, net of allowance for loan losses, respectively Statement of Financial Position [Abstract] Mortgage servicing rights at fair value Servicing Asset at Fair Value, Amount Advances and other receivables, Reserves Advances and Other Receivables, Reserves Advances and Other Receivables, Reserves Reverse mortgage interests, Reserves Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Preferred stock, liquidation preference Preferred Stock, Liquidation Preference, Value Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Unsecured Senior Notes Senior Notes [Member] 2019 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four 2023 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total Debt Instrument, Face Amount Variable Interest Entities and Securitizations [Abstract] Variable Interest Entities and Securitizations Schedule of Assets and Liabilities of VIEs Included in Financial Statements Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value Measurements Fair Value, Measurements, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] IRLCs Interest Rate Lock Commitments [Member] Forward sales of MBS Forward Contracts [Member] LPCs Loan Purchase Commitments [Member] Eurodollar futures Eurodollar Future [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Mortgage loans held for sale Mortgages Held-for-sale, Fair Value Disclosure Mortgage loans held for investment Mortgage servicing rights Derivative financial instruments Derivative Asset, Fair Value, Gross Asset Total assets Assets, Fair Value Disclosure Liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Derivative financial instruments Derivative Liability, Fair Value, Gross Liability Mortgage servicing rights financing Mortgage Servicing Rights Liability Resulting from Sale of Servicer Advances, Rights not Accounted for as a Sale Mortgage Servicing Rights Liability Resulting from Sale or Securitization of Servicer Advances, Rights not Accounted for as a Sale Excess spread financing Excess Spread Financing at Fair Value Excess spread financing (at fair value) Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Derivative instruments at fair value, less than Derivative Instruments in Hedges, at Fair Value, Net Nonrecourse debt–legacy assets Nonrecourse Debt [Member] Nonrecourse Debt Legacy Assets [Member] Participating Interest Financing Participating Interest Financing [Member] Participating Interest Financing [Member] Trust 2017-2 2017-02 HECM Securitization [Member] 2017-02 HECM Securitization [Member] Trust 2018-1 2018-01 HECM Securitization [Member] 2018-01 HECM Securitization [Member] Trust 2018-2 2018-02 HECM Securitization [Member] 2018-02 HECM Securitization [Member] Trust 2018-3 2018-03 HECM Securitization [Member] 2018-03 HECM Securitization [Member] Legacy Asset Legacy Asset [Member] Legacy Asset [Member] Other Other [Member] Other [Member] Securitized Amount Non-recourse debt Non-Recourse Debt Unamortized debt issuance costs, net of premium, and issuance discount Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Operating lease cost Operating Lease, Cost Short-term lease cost Short-term Lease, Cost Sublease income Sublease Income Net lease cost Lease, Cost Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Receivables From Prior Servicers, Reverse Mortgage Interests Receivables From Prior Servicers, Reverse Mortgage Interests [Member] Receivables From Prior Servicers, Reverse Mortgage Interests [Member] Participating Interests in HMBS Participating Interests in HMBS [Member] Participating Interests in HMBS [Member] GNMA Government National Mortgage Association (GNMA) Insured Loans [Member] Trust 2018-1 and Trust 2018-2 Trust 2018-1 and Trust 2018-2 [Member] Trust 2018-1 and Trust 2018-2 [Member] Trust 2016-2 and Trust 2016-3 Trust 2016-2 and Trust 2016-3 [Member] Trust 2016-2 and Trust 2016-3 [Member] Reverse Mortgage Interests, Unsecuritized Reverse Mortgage Interests, Unsecuritized [Member] Reverse Mortgage Interests, Unsecuritized [Member] Other Interest Securitized and Unsecuritized Interests Other Interest Securitized And Unsecuritized Interests [Member] Other Interest Securitized And Unsecuritized Interests [Member] HECM HECM [Member] HECM [Member] Unsecuritized HECM Unsecuritized HECM [Member] Unsecuritized HECM [Member] UPB securitized Reverse Mortgage Interest, Unpaid Principal Balance, Securitized Reverse Mortgage Interest, Unpaid Principal Balance, Securitized UPB sold Reverse Mortgage Interest, Unpaid Principal Balance, Sold Reverse Mortgage Interest, Unpaid Principal Balance, Sold Repurchase of HECM loans Reverse Mortgage Interest, Unsecuritized, Repurchase of Home Equity Conversion Mortgages Reverse Mortgage Interest, Unsecuritized, Repurchase of Home Equity Conversion Mortgages Repurchase of HECM loans funded by prior servicer Reverse Mortgage Interest, Unsecuritized, Repurchase of Home Equity Conversion Mortgages Funded by Prior Servicer Reverse Mortgage Interest, Unsecuritized, Repurchase of Home Equity Conversion Mortgages Funded by Prior Servicer Account receivables Accounts Receivable, Net Purchase discount Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount Interest earned on HECM loans Interest and Fee Income, Loans Held-for-sale, Mortgages 6.500% interest rate payable semi-annually, due July 2021 Unsecured Senior Notes Six Point Five Percent Due July 2021 [Member] Unsecured Senior Notes 6.5% Due July 2021 6.500% interest rate payable semi-annually, due June 2022 Unsecured Senior Notes Six Point Five Percent Due July 2022 [Member] Unsecured Senior Notes Six Point Five Percent Due July 2022 [Member] Interest rate Debt Instrument, Interest Rate, Stated Percentage Unsecured debt Unsecured Debt, Gross Unsecured Debt, Gross Ownership percentage Guarantor Subsidiary, Ownership Percentage Guarantor Subsidiary, Ownership Percentage Number of subsidiaries as guarantors of unsecured debt Number of Subsidiaries as Guarantors of Unsecured Debt Number of Subsidiaries as Guarantors of Unsecured Debt Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Term of lease Lessee, Operating Lease, Term of Contract Term of extension Lessee, Operating Lease, Renewal Term ROU asset Operating Lease, Right-of-Use Asset Operating lease liability Operating Lease, Liability Finance lease liability Finance Lease, Liability Sublease income (less than $1) Net Premium for Participating Interests in HMBS(1) Debt Premium Rollforward [Roll Forward] Debt Premium Rollforward [Roll Forward] Balance - beginning of period Adjustments Debt Instrument, Debt Premium, Additions Debt Instrument, Debt Premium, Additions Utilization of purchase discounts Debt Instrument, Debt Premium, Utilization Of Purchase Discounts Debt Instrument, Debt Premium, Utilization Of Purchase Discounts Amortization Amortization of Debt Discount (Premium) Transfers Debt Instrument, Debt Premium, Transfer Debt Instrument, Debt Premium, Transfer Balance - end of period Net Discount for Other Interest Securitized Other Interest Securitized Rollforward [Roll Forward] Other Interest Securitized Rollforward [Roll Forward] Balance - beginning of period Adjustments Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Additions Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Additions Utilization of purchase discounts Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Utilization Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Utilization Accretion Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Accretion (Amortization) Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Accretion (Amortization) Transfers Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Transfer Reverse Mortgage Interest, Unpaid Principal Balance, Other Interests Securitized, Purchase Discount, Transfer Balance - end of period Net Discount for Unsecuritized Interests Unsecuritized Interests Rollforward [Roll Forward] Unsecuritized Interests Rollforward [Roll Forward] Balance - beginning of period Additions Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Additions Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Additions Utilization of purchase discounts Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Utilization Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Utilization Accretion Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Accretion Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Accretion Transfers Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Transfer Reverse Mortgage Interest, Unpaid Principal Balance, Unsecuritized, Purchase Discount, Transfer Balance - end of period Purchase discounts for reverse mortgage interests Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount Rollforward [Roll Forward] Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount Rollforward [Roll Forward] Balance - beginning of period Additions Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount, Additions Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount, Additions Accretion Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount, Accretion Reverse Mortgage Interest, Unpaid Principal Balance, Purchase Discount, Accretion Balance - end of period Reverse funded loan advances [Table] Schedule of Servicing Assets at Fair Value [Table] Ginnie Mae Loans Ginnie Mae HECM [Member] Ginnie Mae HECM [Member] Servicing Assets at Fair Value [Line Items] Servicing Assets [Line Items] Servicing Assets [Line Items] Delinquent loans acquired Mortgage Loans Held for Sale, Delinquent Loans Acquired Mortgage Loans Held for Sale, Delinquent Loans Acquired Delinquent loans securitized or sold Mortgage Loans Held for Sale, Delinquent Loans Securitized or Sold Mortgage Loans Held for Sale, Delinquent Loans Securitized or Sold Purchased loans that have re-performed Mortgage Loans Held for Sale, Purchased Loans that have Re-performed Mortgage Loans Held for Sale, Purchased Loans that have Re-performed Mortgage loans held for sale in foreclosure Mortgage Loans in Process of Foreclosure, Amount Sale of mortgage loans held for sale Proceeds from Sale of Mortgage Loans Held-for-sale Gain on sale of mortgage loans held for sale Gain on Sale of Mortgage Loans Gain on Sale of Mortgage Loans Mortgage loans held for investment in foreclosure Mortgage Loans Held for Investment in foreclosure, amount mortgage loans held for investment in foreclosure, amount Securitizations and Financings Variable Interest Entities and Securitizations [Text Block] Variable Interest Entities and Securitizations Number of reportable segments Number of Reportable Segments Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Operating Segments Operating Segments [Member] Eliminations Intersegment Eliminations [Member] Corporate and Other Corporate, Non-Segment [Member] Xome Xome Segment [Member] Xome Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Revenues: Revenues [Abstract] Service related, net Fees and Commissions, Mortgage Banking and Servicing Net gain on mortgage loans held for sale Total revenues Revenues Total Expenses Operating Expenses Other income (expenses) Other Nonoperating Income (Expense) [Abstract] Interest income Interest Income, Other Interest expense Interest Expense Other Other Nonoperating Income (Expense) Total other income (expenses), net Nonoperating Income (Expense) (Loss) income before income tax expense (benefit) Depreciation and amortization for property and equipment and intangible assets Total assets Assets Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] RSUs Restricted Stock Units (RSUs) [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Tranche One Share-based Compensation Award, Tranche One [Member] Tranche Two Share-based Compensation Award, Tranche Two [Member] Tranche Three Share-based Compensation Award, Tranche Three [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Certain Employees Certain Employees [Member] Certain Employees [Member] Class of Stock [Line Items] Class of Stock [Line Items] Shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Compensation expense Allocated Share-based Compensation Expense Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Agency MSRs Agency MSRs [Member] Agency MSRs [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Subsidiary of New Residential Subsidiary of New Residential [Member] Subsidiary of New Residential [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Loan Subservicing Agreement Loan Subservicing Agreement [Member] Loan Subservicing Agreement [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] New Residential New Residential [Member] New Residential Related Party Transaction [Line Items] Related Party Transaction [Line Items] Fees paid Payments for Servicing Fees Payments for Servicing Fees Revenue recognized from servicing agreements Contractually Specified Servicing Fees, Late Fees, and Ancillary Fees Earned in Exchange for Servicing Financial Assets, Revenue Recognized Contractually Specified Servicing Fees, Late Fees, and Ancillary Fees Earned in Exchange for Servicing Financial Assets, Revenue Recognized Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Net (loss) income attributable to Successor/Predecessor Less: Undistributed earnings attributable to participating stockholders Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Net (loss) income attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Net (loss) income per common share attributable to Successor/Predecessor: Earnings Per Share, Basic [Abstract] Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Weighted average shares of common stock outstanding (in thousands): Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Dilutive effect of stock awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Dilutive effect of participating securities (in shares) Incremental Common Shares Attributable To Dilutive Effect Of Participating Securities Incremental Common Shares Attributable To Dilutive Effect Of Participating Securities Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Owned Serviced Loans [Table] Subserviced Loans [Table] Subserviced Loans [Table] Owned Service Loans [Line Items] Subserviced Loans [Line Items] Subserviced Loans [Line Items] Fair Value Assets Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash Mortgage servicing rights, $3,481 and $3,665 at fair value, respectively Servicing Asset Advances and other receivables, net of reserves of $71 and $47, respectively Advances and Other Receivables, Net Advances and Other Receivables, Net Reverse mortgage interests, net of reserves of $8 and $13, respectively Mortgage loans held for sale at fair value Mortgage loans held for investment at fair value Property and equipment, net of accumulated depreciation of $27 and $16, respectively Property, Plant and Equipment, Net Deferred tax asset, net Deferred Tax Assets, Net Other assets Other Assets Total assets Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Unsecured senior notes, net Unsecured Debt Advance facilities, net Warehouse facilities, net Notes Payable, Fair Value Disclosure Payables and other liabilities Accounts Payable and Accrued Liabilities MSR related liabilities - nonrecourse at fair value Mortgage Serving Rights Liability, carried at fair value Mortgage Serving Rights Liability, carried at fair value Mortgage servicing liabilities Servicing Liability at Amortized Cost, Balance Other nonrecourse debt, net Total liabilities Liabilities Commitments and contingencies (Note 18) Commitments and Contingencies Preferred stock at $0.00001 - 10 million shares authorized, 1 million shares issued and outstanding, respectively; aggregate liquidation preference of ten dollars, respectively Preferred Stock, Value, Issued Common stock at $0.01 par value - 300 million shares authorized, 91.0 million and 90.8 million shares issued, respectively Common Stock, Value, Issued Additional paid-in-capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Total Mr. Cooper stockholders’ equity Stockholders' Equity Attributable to Parent Non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Mortgage Banking [Abstract] Capital Requirements Regulatory Capital Requirements for Mortgage Companies Disclosure [Text Block] Loans subject to repurchase from Ginnie Mae Assets Sold under Agreements to Repurchase, Repurchase Liability Schedule of Payables and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Schedule of Loans Subject to Repurchase Reserve Schedule of Loans Subject to Repurchase Reserve [Table Text Block] Schedule of Loans Subject to Repurchase Reserve [Table Text Block] Contractually specified servicing fees Contractually Specified Servicing Fees, Amount Other service-related income Other Service Related Income Other Service Related Income Incentive and modification income Servicing Fee Income, Incentive and Modification Income Servicing Fee Income, Incentive and Modification Income Late fees Late Fee Income Generated by Servicing Financial Assets, Amount Reverse servicing fees Reverse Servicing Fees, Amount Reverse Servicing Fees, Amount Mark-to-market adjustments Servicing Fee Income, Mark to Market Adjustment Servicing Fee Income, Mark to Market Adjustment Counterparty revenue share Servicing Fee Income, Counter Party Revenue Share Servicing Fee Income, Counter Party Revenue Share Amortization, net of accretion Servicing Fee Income, Amortization Servicing Fee Income, Amortization Total servicing revenue Servicing Fee Income, Net Servicing Fee Income, Net Minimum net worth required for compliance Minimum Net Worth Required for Compliance Cash and cash equivalents Total cash, cash equivalents, and restricted cash Mortgage servicing right at amortized cost Servicing Asset at Amortized Cost Mortgage servicing rights - fair value and amortized cost Mortgage servicing liabilities - amortized cost Excess spread financing - fair value Excess Spread Financing, Fair Value Disclosure Excess Spread Financing, Fair Value Disclosure Mortgage servicing rights financing - fair value MSR related liabilities - nonrecourse at fair value Operating Leases Operating Lease Liabilities, Payments Due [Abstract] 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five 2024 and thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total minimum lease payments Lessee, Operating Lease, Liability, Payments, Due Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Total lease liabilities Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Xome Holdings LLC Xome Holdings LLC [Member] Xome Holdings LLC [Member] Assurant Mortgage Solutions Group Assurant Mortgage Solutions Group [Member] Assurant Mortgage Solutions Group [Member] Cash consideration Payments to Acquire Businesses, Gross Contingent consideration Business Combination, Contingent Consideration, Liability Estimated consideration Business Combination, Consideration Transferred Intangible assets acquired Finite-lived Intangible Assets Acquired Goodwill acquired Goodwill, Acquired During Period Change in contingent consideration Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Mr. Cooper Restricted cash Restricted Cash and Cash Equivalents Mortgage servicing rights Advances and other receivables, net Reverse mortgage interests, net Property and equipment, net Investment in subsidiaries Investment in Consolidated Subsidiaries Investment in Consolidated Subsidiaries Liabilities and Stockholders’ Equity Advance facilities Warehouse facilities Mortgage servicing liabilities Payables to affiliates Due to Affiliate Total stockholders' equity UPB Mortgage Loans Held For Investment, Nonaccrual Basis, Unpaid Principal Balance Mortgage Loans Held For Investment, Nonaccrual Basis, Unpaid Principal Balance Fair Value Mortgage Loans Held For Investment, Nonaccrual Basis, Fair Value Mortgage Loans Held For Investment, Nonaccrual Basis, Fair Value Mortgage Loans Held For Investment [Roll Forward] Mortgage Loans Held For Investment [Roll Forward] Mortgage Loans Held For Investment [Roll Forward] Balance - beginning of period Payments received from borrowers Proceeds From Collection Of Mortgage Loans Held For Investment Proceeds From Collection Of Mortgage Loans Held For Investment Changes in fair value Balance - end of period Schedule of Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Business Acquisitions Schedule of Business Acquisitions, by Acquisition [Table Text Block] Pro Forma Information Business Acquisition, Pro Forma Information [Table Text Block] Schedule of Servicing Assets at Fair Value Schedule of Servicing Assets at Fair Value [Table Text Block] Schedule of Assumptions for Fair Value of Mortgage Service Rights Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table Text Block] Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Schedule of Fees Earned in Exchange for Servicing Financial Assets Schedule of Fees Earned in Exchange for Servicing Financial Assets [Table Text Block] Schedule of Fees Earned in Exchange for Servicing Financial Assets [Table Text Block] Reverse Mortgage Interests Reserves [Roll Forward] Reverse Mortgage Interests Reserves [Roll Forward] Reverse Mortgage Interests Reserves [Roll Forward] Balance - beginning of period Provision Reverse Mortgage Reserves, Period Increase Through Provision for Loan Loss Adjustments Reverse Mortgage Reserves, Period Increase Through Provision for Loan Loss Adjustments Write-offs Reverse Mortgage Reserves, Period Decrease Related to Charge Offs Reverse Mortgage Reserves, Period Decrease Related to Charge Offs Balance - end of period Mortgage Loans Held for Sale and Investment Financing Receivables [Text Block] Income Taxes Income Tax Disclosure [Text Block] Accounts Payable [Table] Accounts Payable [Table] Accounts Payable [Table] Accounts Payable [Line Items] Accounts Payable [Line Items] [Line Items] for Accounts Payable [Table] Loans Subject to Repurchase Reserve [Roll Forward] Loans Subject to Repurchase Reserve [Roll Forward] Loans Subject to Repurchase Reserve [Roll Forward] Balance - beginning of period Repurchase Reserve Repurchase Reserve Provisions Repurchase Reserve, Additions Repurchase Reserve, Additions Releases Repurchase Reserve, Reductions Repurchase Reserve, Reductions Charge-offs Repurchase Reserve, Charge-offs Repurchase Reserve, Charge-offs Balance - end of period Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Mortgage loans held for investment Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Mortgage servicing rights financing Mortgage Servicing Right Liability [Member] Mortgage Servicing Right Liability Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance - beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total gains or losses included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Payments received from borrowers Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Payments Received Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Payments Received Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Issuances Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Repayments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Repayments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Repayments Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Balance - end of period Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance - beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Total gains or losses included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Payments received from borrowers Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments Received Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments Received Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Issuances Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales Repayments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Repayments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Repayments Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Balance - end of period Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table] Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table] Residential Mortgage Residential Mortgage [Member] Other nonrecourse debt Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Restricted cash Restricted Cash [Member] Restricted Cash [Member] Advances and other receivables, net Accounts Receivable [Member] Other assets Other Assets [Member] Advance facilities Notes Payable [Member] Notes Payable [Member] Payables and other liabilities Accounts Payable and Accrued Liabilities [Member] Participating interest financing Other non-recourse debt Other Non-Recourse Debt [Member] Other Non-Recourse Debt Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] Number of SPEs Number Of Variable Interest Entities Number Of Variable Interest Entities Assets Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount Reverse Secured Borrowings, Assets, Carrying Amount Reverse Secured Borrowings, Assets, Carrying Amount Reverse Secured Borrowings, Assets, Carrying Amount Liabilities Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount Reverse Secured Borrowings, Liabilities, Carrying Amount Reverse Secured Borrowings, Liabilities, Carrying Amount Reverse Secured Borrowings, Liabilities, Carrying Amount Loans subject to repurchase from Ginnie Mae Resell Agreement, Loans and Leases Receivable Resell Agreement, Loans and Leases Receivable Accrued revenues Servicing Fees Receivable Servicing Fees Receivable Right-of-use assets Intangible assets Intangible Assets, Net (Excluding Goodwill) Goodwill Other Other Assets, Miscellaneous Total other assets Schedule of Servicing Assets at Fair Value [Table] Servicing Assets at Fair Value [Line Items] Servicing Assets at Fair Value [Line Items] Servicing Asset at Fair Value, Amount [Roll Forward] Servicing Asset at Fair Value, Amount [Roll Forward] Fair value - beginning of period Servicing retained from mortgage loans sold Servicing Asset at Fair Value, Additions, Servicing Retained From Mortgage Loans Sold Servicing Asset at Fair Value, Additions, Servicing Retained From Mortgage Loans Sold Purchases of servicing rights Servicing Asset at Fair Value, Additions Sales of servicing assets Servicing Asset at Fair Value, Disposals Changes in valuation inputs or assumptions used in the valuation model Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Other changes in fair value Servicing Asset at Fair Value, Other Changes in Fair Value Fair value - end of period Ginnie Mae Repurchased Loans Ginnie Mae Repurchased Loans [Member] Ginnie Mae Repurchased Loans [Member] Mortgage loans held for sale – UPB Loans Held-for-Sale, Mortgages, Unpaid Principal Balance Loans Held-for-Sale, Mortgages, Unpaid Principal Balance Mark-to-market adjustment Loans Held-for-Sale, Mortgages, Fair Value Adjustment Loans Held-for-Sale, Mortgages, Fair Value Adjustment Total mortgage loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage UPB Mortgage Loans Held for Sale, Nonaccrual Basis Unpaid Principal Balance Mortgage Loans Held for Sale, Nonaccrual Basis Unpaid Principal Balance Fair Value Fair Value, Mortgage Loans Held for Sale non-accrual status Fair Value, Mortgage Loans Held for Sale non-accrual status Fair Value Measurements Fair Value Disclosures [Text Block] Reverse Mortgage Interest Reverse Mortgage Interest [Table Text Block] Reverse Mortgage Interest [Table Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Income Statement [Abstract] Net gain on mortgage loans held for sale Total revenues Expenses: Operating Expenses [Abstract] Salaries, wages and benefits Labor and Related Expense General and administrative General and Administrative Expense Total expenses Other income (expenses): Nonoperating Income (Expense) [Abstract] Other income (expenses) Less: Income tax (benefit) expense Net (loss) income Less: Net (loss) income attributable to non-controlling interests Net (loss) income per common share attributable to Successor/Predecessor: Schedule of Derivative Instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Guarantor Financial Statement Information Guarantor Financial Statement Information Disclosure [Text Block] Guarantor Financial Statement Information Receivables [Abstract] Servicing advances, net of $169 and $205 discount, respectively Servicing Advances Servicing Advances