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Common equity tier 1 capital Tier One Common Risk Based Capital to Total Risk Weighted Assets Tier one common risk-based capital to total risk-weighted assets Capital ratio: required tier 1 capital Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 capital Tier One Risk Based Capital to Risk Weighted Assets Capital ratio: required total capital Capital Required for Capital Adequacy to Risk Weighted Assets Total capital Capital to Risk Weighted Assets Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2017 Stock Incentive Plan 2017 Stock Incentive Plan [Member] 2017 Stock Incentive Plan [Member] 2006 Equity Incentive Plan 2006 Equity Incentive Plan [Member] 2006 Equity Incentive Plan 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Value, Gross Asset and Right to Reclaim Cash, Offset Derivative liability Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement Derivative liability, Impact of Netting Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset Derivative liabilities Derivative Liability Other Other Liabilities, Fair Value Disclosure Total liabilities carried at fair value Financial and Nonfinancial Liabilities, Fair Value Disclosure Derivative asset, collateral, cash offset Derivative Asset, Collateral, Obligation to Return Securities and Cash, Offset Derivative Asset, Collateral, Obligation to Return Securities and Cash, Offset Derivative liability, collateral, cash offset Derivative Liability, Collateral, Right to Reclaim Securities and Cash, Offset Derivative Liability, Collateral, Right to Reclaim Securities and Cash, Offset Earnings Per Share [Abstract] Net income Net Income (Loss) Attributable to Parent Preferred stock dividends Dividends, Preferred Stock Dividends and undistributed earnings allocated to participating securities Dividends and undistributed earnings allocated to participating securities Allocation to participating securities, which are composed of holders of unvested restricted stock and director stock; have non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders. Net income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Basic average common shares Weighted Average Number of Shares Outstanding, Basic Effect of dilutive securities: common stock options and common stock awards (in shares) Stock Options And Stock Awards Stock Options And Stock Awards Diluted average common shares Weighted Average Number of Shares Outstanding, Diluted Anti-dilutive securities (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Earnings per Common Share: Earnings Per Share, Basic and Diluted [Abstract] Basic (in USD per share) Earnings Per Share, Basic Diluted (in USD per share) Earnings Per Share, Diluted Segment Reporting [Abstract] Summary of Line of Business Results Schedule of Segment Reporting Information, by Segment [Table Text Block] Leases [Abstract] Capital Leases Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Capital leases due 2019 Capital 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Future Minimum Payments, Due in Two Years Operating leases due 2021 Operating Leases, Future Minimum Payments, Due in Three Years Operating leases due 2022 Operating Leases, Future Minimum Payments, Due in Four Years Operating leases due 2023 Operating Leases, Future Minimum Payments, Due in Five Years Operating leases due thereafter Operating Leases, Future Minimum Payments, Due Thereafter Operating leases due Operating Leases, Future Minimum Payments Due Total operating and capital leases due 2019 Capital And Operating Leases Future Minimum Payments Due Current Capital And Operating Leases Future Minimum Payments Due Current Total operating and capital leases due 2020 Capital And Operating Leases Future Minimum Payments Due In Two Years Capital And Operating Leases Future Minimum Payments Due In Two Years Total operating and capital leases due 2021 Capital And Operating Leases Future Minimum Payments Due In Three Years Capital And Operating Leases Future Minimum Payments Due In Three Years Total operating and capital leases due 2022 Capital And Operating Leases Future Minimum Payments Due In Four Years Capital And Operating Leases Future Minimum Payments Due In Four Years Total operating and capital leases due 2023 Capital And Operating Leases Future Minimum Payments Due In Five Years Capital And Operating Leases Future Minimum Payments Due In Five Years Total operating and capital leases due thereafter Capital And Operating Leases Future Minimum Payments Due There after Capital And Operating Leases Future Minimum Payments Due There after Total operating and capital leases due Capital And Operating Leases Future Minimum Payments Due Capital And Operating Leases Future Minimum Payments Due Retirement Benefits [Abstract] Employee Benefits Compensation and Employee Benefit Plans [Text Block] Class of Treasury Stock [Table] Class of Treasury Stock [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2017 Program Two Thousand and Seventeen Share Repurchase Program [Member] Two Thousand and Seventeen Share Repurchase Program [Member] 2018 Program Two Thousand and Eighteen Share Repurchase Program [Member] Two Thousand and Eighteen Share Repurchase Program [Member] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Shares issued (shares) Stock Issued During Period, Shares, New Issues Offering price of shares issued (USD per share) Shares Issued, Price Per Share Proceeds from issuance of common stock, net of issuance costs Proceeds from Issuance of Common Stock Amount of common stock authorized for repurchase Stock Repurchase Program, Authorized Amount Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series C Preferred Stock Series C Preferred Stock [Member] Series C Preferred Stock, Depository Share Series C Preferred Stock, Depository Share [Member] Series C Preferred Stock, Depository Share [Member] Series D Preferred Stock Series D Preferred Stock [Member] Series D Preferred Stock, Depository Share Series D Preferred Stock, Depository Share [Member] Series D Preferred Stock, Depository Share [Member] Series E Preferred Stock Series E Preferred Stock [Member] Series E Preferred Stock, Depository Share Series E Preferred Stock, Depository Share [Member] Series E Preferred Stock, Depository Share [Member] Series F Preferred Stock Series F Preferred Stock [Member] Series F Preferred Stock, Depository Share Series F Preferred Stock, Depository Share [Member] Series F Preferred Stock, Depository Share 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Preference Stock Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Investment Servicing Investment Servicing [Member] Investment Servicing Member Investment Management Investment Management [Member] Investment Management [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Beginning balance Goodwill Acquisitions Goodwill, Acquired During Period Divestitures and other reductions Goodwill, Written off Related to Sale of Business Unit Foreign currency translation Goodwill, Translation and Purchase Accounting Adjustments Ending balance Equity-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Commitments and Guarantees Commitments and Guarantees Disclosure [Text Block] The entire disclosure for significant commitments and guarantees, which include commitments to extend credit and off-balance sheet guarantees composed of indemnified securities financing, stable value protection, unfunded commitments to purchase assets, and standby letters of credit. Dividends Payable [Table] Dividends Payable [Table] Dividends Payable [Line Items] Dividends Payable [Line Items] Cash dividends declared (in USD per share) Common Stock, Dividends, Per Share, Declared Common stock dividends Dividends, Common Stock, Cash Offsetting [Abstract] Offsetting Arrangements Offsetting Arrangements [Text Block] Offsetting Arrangements [Text Block] Shares Acquired (in shares) Stock Repurchased During Period, Shares Average Cost per Share (USD per share) Treasury Stock Acquired, Average Cost Per Share Total Acquired Stock Repurchased During Period, Value Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Beginning of Period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Paid Out (in shares) Paid out, shares Paid out, shares End of Period (in shares) Weighted-Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Beginning of Period (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Forfeited (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than 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[Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] One Lincoln Street One Lincoln Street [Member] One Lincoln Street [Member] Property Subject to or Available for Operating Lease [Line Items] Property Subject to or Available for Operating Lease [Line Items] Depreciation Depreciation Leased area (in sqft) Leased Area Leased Area Noncancelable capital leases expiration Noncancelable capital leases expiration Noncancelable Capital Leases Expiration Sublease building (in sqft) Sublease Building Sublease Building Capital lease obligation Capital Lease Obligations Interest expense on capital lease Interest Expense, Lessee, Assets under Capital Lease Accumulated amortization on capital lease Capital Leases, Net Investment in Direct Financing Leases, Accumulated Amortization Sublease rental expense Operating Leases, Rent Expense, Sublease Rentals Sublease revenue Operating Leases, Income Statement, Sublease Revenue Future minimum sublease rental revenue on capital lease Capital Leases, Future Minimum Sublease Rentals Future minimum sublease rental revenue on operating lease Operating Leases Future Minimum Payments Due Current Decrease Operating Leases Future Minimum Payments Due Current Decrease Condensed Financial Information Disclosure [Abstract] Parent Company Financial Statements Condensed Financial Information of Parent Company Only Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivatives not designated as hedging instruments Not Designated as Hedging Instrument [Member] Hedged Items Currently Designated Designated as Hedging Instrument [Member] Commodity and Equity Contracts Commodity and Equity Contracts [Member] Commodity and Equity Contracts [Member] Other derivative contracts Other Contract [Member] Futures Future [Member] Forward, swap and spot Forward Swap And Spot [Member] Forward, Swap And Spot [Member] Options purchased Options Purchased [Member] Options Purchased [Member] Options written Options Written [Member] Options Written [Member] Commodity Commodity Contract [Member] Equity Equity Contract [Member] Stable value contracts Stable Value Contracts [Member] Stable Value Contracts [Member] Deferred value awards Deferred Value Awards [Member] Deferred Value Awards [Member] Swap agreements Swap [Member] Forward and swap Forwards [Member] Forwards [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Notional amount of derivative instruments Derivative, Notional Amount Fair value of indemnified securities financing Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing Aggregate Fair Value Of Cash And Securities Held As Collateral For Indemnified Securities Aggregate Fair Value Of Cash And Securities Held As Collateral For Indemnified Securities Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements Collateral for Indemnified Securities Invested in Indemnified Repurchase Agreements Collateral for indemnified securities invested in indemnified repurchase agreements Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements Aggregate Fair Value Of Cash And Securities Held As Collateral For Indemnified Repurchase Agreements Aggregate Fair Value Of Cash And Securities Held As Collateral For Indemnified Repurchase Agreements Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Management fees Management Services [Member] Management Services [Member] Foreign exchange trading services Foreign Exchange Trading Services [Member] Foreign Exchange Trading Services. Other Services Other Services [Member] Other Services [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2018-02 Accounting Standards Update 2018-02 [Member] Accounting Standards Update 2018-02 [Member] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2017-12 Accounting Standards Update 2017-12 [Member] Accounting Standards Update 2016-01 Accounting Standards Update 2016-01 [Member] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Difference between Revenue Guidance in Effect before and after Topic 606 Difference between Revenue Guidance in Effect before and after Topic 606 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Right-of-use assets Operating Lease, Right-of-Use Asset Lease liabilities Operating Lease, Liability Stranded tax effects reclassified Tax Cuts And Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect Tax Cuts And Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect Increase in revenues Revenues Increase in management fees Fees And Commissions, Management Fees Fees And Commissions, Management Fees Increase in trading services revenue Fees And Commissions, Foreign Exchange Trading Services Fees And Commissions, Foreign Exchange Trading Services Increase in other revenue lines Other Revenue Other Revenue Increase in expenses Noninterest Expense Increase in other expenses Other Expenses Increase in transaction processing Floor Brokerage, Exchange and Clearance Fees Increase in all other expenses Other Cost and Expense, Operating Investment securities available-for-sale Debt securities, held-to-maturity Debt Securities, Held-to-maturity Money market funds reclassified Money Market Funds, at Carrying Value Available-for-sale equity securities reclassified Equity Securities, FV-NI Statement of Cash Flows [Abstract] Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Deferred income tax (benefit) Deferred Income Tax Expense (Benefit) Amortization of other intangible assets Amortization of Intangible Assets Other non-cash adjustments for depreciation, amortization and accretion, net Noncash Adjustments For Depreciation Amortization Accretion The aggregate net amount of depreciation, amortization, and accretion, excluding amortization of intangibles, recognized during the period. (Gains) losses related to investment securities, net Marketable Securities, Gain (Loss) Change in trading account assets, net Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI Change in accrued interest and fees receivable, net Increase (Decrease) in Other Receivables Change in collateral deposits, net Increase (Decrease) in Cash Collateral for Loaned Securities Change in unrealized (gains) losses on foreign exchange derivatives, net Change in Unrealized Gains (Losses) Related to Financial Instruments Change In Unrealized Gains Losses Related To Financial Instruments Change in other assets, net Increase (Decrease) in Other Operating Assets Change in accrued expenses and other liabilities, net Increase (Decrease) in Other Operating Liabilities Other, net Other Noncash Income (Expense) Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities: Net Cash Provided by (Used in) Investing Activities 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Cash and Due from Banks Cash and due from banks at end of period Supplemental disclosure: Supplemental Cash Flow Information [Abstract] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes paid, net Income Taxes Paid, Net Loans and Leases Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Schedule of Stock Options and Stock Appreciation Rights Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Deferred Stock Awards Schedule Of Deferred Stock Awards Activity [Table Text Block] Schedule Of Deferred Stock Awards Activity [Table Text Block] Schedule of Performance Awards Share-based Compensation, Performance Shares Award Outstanding Activity [Table Text Block] Statement of Comprehensive Income [Abstract] Foreign currency translation, Taxes Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Change in net unrealized losses on available-for-sale securities, Taxes Other 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Share Earnings Per Share [Text Block] Summary of Future Minimum Lease Payments Under Non Cancelable Capital and Operating Leases Summary Of Future Minimum Lease Payments Under Non Cancelable Capital And Operating Leases [Table Text Block] Summary Of Future Minimum Lease Payments Under Non Cancelable Capital And Operating Leases [Table Text Block] Debt Disclosure [Abstract] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Securities Sold Under Repurchase Agreements Securities Sold under Agreements to Repurchase [Member] Tax-Exempt Investment Program Tax-exempt Money Market Funds [Member] Other Other Short-Term Borrowings [Member] Other Short-Term Borrowings [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] Balance as of December 31 Short-term Debt Maximum outstanding as of any month-end Short-term Debt, Maximum Month-end Outstanding Amount Average outstanding during the year Short-term Debt, Average Outstanding Amount Weighted-average interest rate as of year-end Short-term Debt, Weighted Average Interest Rate, at Point in Time Weighted-average interest rate during the year Short Term Debt Weighted Average Interest Rate During The Period Short Term Debt Weighted Average Interest Rate During The Period Income Tax Disclosure [Abstract] Valuation Allowance [Table] Valuation Allowance [Table] Valuation Allowance by Deferred Tax Asset [Axis] Valuation Allowance by Deferred Tax Asset [Axis] Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] General business Credits General Business Tax Credit Carryforward [Member] NOLs - Non-U.S. Operating Loss Carryforwards, Foreign [Member] Operating Loss Carryforwards, Foreign [Member] Other Carryforwards Other Tax Carryforwards [Member] Other Tax Carryforwards [Member] NOLs - State Operating Loss Carryforwards, State and Local [Member] Operating Loss Carryforwards, 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Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and due from banks Interest-bearing deposits with banks Interest-bearing Deposits in Banks and Other Financial Institutions Securities purchased under resale agreements Securities Purchased under Agreements to Resell Net loans (excluding leases) Loans Held-for-sale, Fair Value Disclosure Financial Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Non-interest-bearing Noninterest-bearing Deposit Liabilities Interest-bearing - U.S. Interest-bearing Deposit Liabilities, Domestic Interest-bearing - non-U.S. Interest-bearing Deposit Liabilities, Foreign Securities sold under repurchase agreements Securities Sold under Agreements to Repurchase Other short-term borrowings Other Short-term Borrowings Long-term debt Long-term Debt, Fair Value Contractual Maturities Of Debt Investment Securities [Table] Contractual Maturities Of Debt Investment Securities [Table] Contractual Maturities of Debt Investment Securities [Table] Contractual Maturities Of Debt Investment Securities [Line Items] Contractual Maturities Of Debt Investment Securities [Line Items] Contractual Maturities Of Debt Investment Securities [Line Items] Available for sale, under 1 Year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Available for sale, 1 to 5 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Available for sale, 6 to 10 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Available for sale, over 10 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Available-for-sale, fair 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Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Net Unrealized Gains (Losses) on Available-for-Sale Securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Other-Than-Temporary Impairment on Securities Accumulated Other-than-Temporary Impairment Attributable to Parent [Member] Amortization of Actuarial Losses Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Foreign Currency Translation Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Gains (losses) from sales of available-for-sale securities, net Debt Securities, Available-for-sale, Realized Gain (Loss), Excluding 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Adjustment from AOCI, Tax Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Current Assets: Assets, Current [Abstract] Investment securities held-to-maturity, fair value Loans and leases, allowance for losses Loans and Leases Receivable, Allowance Premises and equipment, accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Stockholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, no par value (in USD per share) Preferred Stock, No Par Value Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock, shares (in shares) Treasury Stock, Shares Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Parent Company and Non-banking Subsidiaries Parent Company and Non-banking Subsidiaries [Member] Parent Company and Non-banking Subsidiaries [Member] State Street Bank State Street Bank [Member] State Street Bank [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior notes Senior Notes [Member] Subordinated note Subordinated Debt [Member] Junior Subordinated Debt Junior Subordinated Debt [Member] Capital Lease Obligations Capital Lease Obligations [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 3.55% notes due 2025 Three Point Five Five Percent Notes Due 2025 [Member] Three Point Five Five Percent Notes Due 2025 [Member] 2.55% notes due 2020 Two Point Five Five Percent Note Due 2020 [Member] Two Point Five Five percent note due 2020 [Member] 3.7% notes due in 2023 Three Point Seven Zero Percent Senior Notes Due 2023 [Member] Three Point Seven Zero Percent Senior Notes Due 2023 [Member] 3.3% notes due 2024 Three Point Three Zero Percent Notes Due 2024 [Member] Three Point Three Zero Percent Notes Due 2024 [Member] 3.1% subordinated notes due 2023 Three Point One Subordinated Notes Due 2023 [Member] Three Point One Subordinated Notes Due 2023 [Member] Floating-rate subordinated notes due to State Street Capital Trust IV in 2037 Floating Rate Subordinated Notes Due 2037 [Member] Floating Rate Subordinated Notes Due In 2037 [Member] 2.653% notes due 2023 Two Point Six Five Three Notes Due 2023 [Member] Two Point Six Five Three Notes Due 2023 [Member] 4.375% notes due 2021 Four Point Three Seven Five Notes Due2021 [Member] Four Point Three Seven Five Notes Due 2021 [Member] 1.95% Notes Due 2021 One Point Nine Five Percent Notes Due 2021 [Member] One Point Nine Five Percent Notes Due 2021 [Member] 2.65% notes due 2026 Two Point Six Five Percent Notes Due 2026 [Member] Two Point Six Five Percent Notes Due 2026 [Member] 4.141% Notes Due 2029 Four Point One Four One Percent Notes Due 2029 [Member] Four Point One Four One Percent Notes Due 2029 [Member] 3.776% Notes Due 2024 Three Point Seven Seven Six Percent Notes Due 2024 [Member] Three Point Seven Seven Six Percent Notes Due 2024 [Member] Floating-rate notes due 2020 Floating Rate Notes Due 2020 [Member] Floating Rate Notes Due 2020 [Member] Floating-rate subordinated notes due to State Street Capital Trust I in 2028 Floating Rate Subordinated Notes Due 2028 [Member] Floating Rate Subordinated Notes Due In 2028 [Member] 7.35% notes due 2026 Seven Point Three Five Percent Notes Due2026 [Member] Seven Point Three Five Percent Notes Due 2026 [Member] 4.956% junior subordinated debentures due 2018 Four Point Nine Five Six Percent Junior Subordinated Debentures Due2018 [Member] Four Point Nine Five Six Percent Junior Subordinated Debentures Due 2018 [Member] 1.35% notes due 2018 One Point Three Five Percent Senior Notes Due 2018 [Member] One Point Three Five Percent Senior Notes Due 2018 [Member] 5.25% subordinated notes due 2018 Five Point Two Five Percent Subordinated Notes Due2018 [Member] Five Point Two Five Percent Subordinated Notes Due 2018 [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Fair Value Hedges Fair Value Hedging [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Interest rate on debt Debt Instrument, Interest Rate, Stated Percentage Long-term debt Long-term Debt Long-term capital leases Long-term Debt and Capital Lease Obligations Total long-term debt Long-term Debt and Capital Lease Obligations, Including Current Maturities Increase (decrease) in carrying value of long-term debt Increase (Decrease) In Carrying Value Of Long Term Debt Increase (Decrease) In Carrying Value Of Long Term Debt Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Parent Company Parent Company [Member] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Net cash provided by operating activities Net decrease (increase) in interest-bearing deposits with consolidated banking subsidiary Proceeds from sales and maturities of available-for-sale securities Purchases of available-for-sale securities Investments in consolidated banking and non-banking subsidiaries Investments in non-banking subsidiaries and unconsolidated entities Investments in non-banking subsidiaries and unconsolidated entities Sale or repayment of investment in consolidated banking and non-banking subsidiaries Sale Of Investment In Non-Banking Subsidiaries And Unconsolidated Entities Sale Of Investment In Non-Banking Subsidiaries And Unconsolidated Entities Business acquisitions Net increase in investments in unconsolidated affiliates Payments to Acquire Interest in Subsidiaries and Affiliates Payments for long-term debt Repurchases of common stock Payments for cash dividends Net change Net Interest Income Interest Income and Interest Expense Disclosure [Text Block] Allowance for Loan and Lease Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Beginning balance Financing Receivable, Allowance for Credit Losses Provision for loan and lease losses Provision for Loan and Lease Losses Charge-offs Allowance for Loan and Lease Losses, Write-offs Ending balance Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table] Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table] Agency Securities Agency Securities [Member] Residential Mortgage Backed Securities Residential Mortgage Backed Securities [Member] Commercial Mortgage Backed Securities Commercial Mortgage Backed Securities [Member] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items] Available-for-sale equity securities reclassified Available-for-sale Securities, Equity Securities Pledged securities not separately reported Pledged Financial Instruments, Not Separately Reported, Securities Loss from sale of HTM securities Debt Securities, Held-to-maturity, Sold, Realized Gain (Loss) Securities sold Debt Securities, Available-For-Sale, Sold Security, at Carrying Value Debt Securities, Available-For-Sale, Sold Security, at Carrying Value Pre-tax gain on sale of securities Debt Securities, Available-for-sale, Realized Gain (Loss) Debt securities, available-for-sale, transferred security, at carrying value Debt Securities, Available-For-Sale, Transferred Security, At Carrying Value Debt Securities, Available-For-Sale, Transferred Security, At Carrying Value Debt securities, available-for-sale, unrealized gain (loss) Debt Securities, Available-for-sale, Unrealized Gain (Loss) Debt securities, available-for-sale, security term Debt Securities, Available-For-Sale, Securities Transferred, Security Term Debt Securities, Available-For-Sale, Securities Transferred, Security Term Losses from other-than-temporary impairment Other than Temporary Impairment Losses, Investments Asset backed securities, average remaining,term Asset Backed Securities, Average Remaining,Term Asset Backed Securities, Average Remaining,Term Total exposure (less than) Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure Gross pre-tax unrealized losses Marketable Securities, Unrealized Gain (Loss), Excluding Other-than-temporary Impairment Loss Number of securities in loss position Available-for-sale and Held-to-Maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity or available-for-sale where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity and available-for-sale investments determined to be temporarily impaired. Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Derivative Assets at Fair Value Schedule of Derivative Assets at Fair Value [Table Text Block] Schedule of Derivative Liabilities at Fair Value Schedule of Derivative Liabilities at Fair Value [Table Text Block] Impact of Derivative Financial Instruments On Statement of Income Derivative Instruments, Gain (Loss) [Table Text Block] Schedule of Outstanding Hedges: (Notional Amount) Schedule of Derivative Instruments [Table Text Block] Number of lines of business Number of Reportable Segments Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Net Unrealized Gains (Losses) on Cash Flow Hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries Accumulated Net Unrealized Gain (Loss) on Net Investment Hedging [Member] Accumulated Net Unrealized Gain (Loss) on Net Investment Hedging [Member] Other-Than-Temporary Impairment on Held-to-Maturity Securities Net Unrealized Losses on Retirement Plans Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Other comprehensive income (loss) before reclassifications OCI, before Reclassifications, Net of Tax, Attributable to Parent Amounts reclassified into (out of) earnings Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Ending balance Condensed Financial Information Statement of Income of Parent Company Condensed Income Statement [Table Text Block] Condensed Financial Information Statement of Condition of Parent Company Condensed Balance Sheet [Table Text Block] Condensed Financial Information Statement of Cash Flows of Parent Company Condensed Cash Flow Statement [Table Text Block] Other Income and Expenses [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] Business Operations and IT Operations and Information Technology Restructuring Plan [Member] Operations and Information Technology Restructuring Plan [Member] State Street Beacon State Street Beacon [Member] State Street Beacon [Member] Repositioning Repositioning [Member] Repositioning [Member] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee Related Costs Employee Severance [Member] Real Estate Actions Facility Closing [Member] Asset and Other Write-offs Assets and Other Write-offs [Member] Assets and Other Write-offs [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Beginning balance Restructuring Reserve Accruals Restructuring Charges Payments and Other Adjustments Payments for Restructuring Ending balance Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Accrued expenses and other liabilities Accrued Expenses And Other Liabilities [Member] Accrued Expenses and Other Liabilities [Member] Total derivative instruments Derivative Financial Instruments, Liabilities [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] 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] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] 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] Client relationships Customer Relationships [Member] Core deposits Core Deposits [Member] Technology Technology-Based Intangible Assets [Member] Other Other Intangible Assets [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Amount Finite-Lived Intangible Assets, Net Other Expenses [Abstract] Schedule of Expenses Schedule of Other Operating Cost and Expense, by Component [Table Text Block] Restructuring and Related Costs Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Offsetting Liabilities [Table] Offsetting Liabilities [Table] Offsetting Liabilities [Line Items] Offsetting Liabilities [Line Items] Derivatives, Gross amounts of recognized liabilities Derivative Liability, Fair Value, Gross Liability Derivatives, Gross amounts offset in statement of condition Derivative Liability, Fair Value, Gross Asset Derivatives, Net Amounts of Liabilities Presented in Statement of Condition Derivative Liability, Fair Value, Amount Not Offset Against Collateral Derivative, Net Amount Derivative Liability, Fair Value, Amount Offset Against Collateral Derivatives, Cash and collateral securities netting, offset Derivatives, Cash and collateral securities netting, Cash and Securities Provided Derivative, Collateral, Right to Reclaim Securities and Cash Derivative, Collateral, Right to Reclaim Securities and Cash Derivatives, Cash and collateral securities netting, Net Derivative, Collateral, Right to Reclaim Securities and Cash, Net of Offset Derivative, Collateral, Right to Reclaim Securities and Cash, Net of Offset Resale agreements and securities lending, Gross Amounts of Recognized Liabilities(1)(2) Reverse Repurchase Agreements and Securities Borrowing, Fair Value, Gross Liability Reverse Repurchase Agreements and Securities Borrowing, Fair Value, Gross Liability Resale agreements and securities lending, Gross Amounts Offset in Statement of Condition(3) Reverse Repurchase Agreements and Securities Borrowed, Asset Reverse Repurchase Agreements and Securities Borrowed, Asset Resale agreements and securities lending, Net Amounts of Liabilities Presented in Statement of Condition Repurchase Agreements and Securities Lending, Fair Value, Amount Not Offset Against Collateral Repurchase Agreements and Securities Lending, Fair Value, Amount Not Offset Against Collateral Resale agreements and securities lending, Cash and Securities Provided Repurchase Agreements and Securities Loaned, Collateral, Right to Reclaim Cash Repurchase Agreements and Securities Loaned, Collateral, Right to Reclaim Cash Resale agreements and securities lending, Net Amount Repurchase Agreements and Securities Loaned, Amount Offset Against Collateral Repurchase Agreements and Securities Loaned, Amount Offset Against Collateral Total derivatives and other financial instruments, Gross Amounts of Recognized Liabilities Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross Total derivatives and other financial instruments, Gross Amounts Offset in Statement of Condition Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset Total derivatives and other financial instruments, Net Amounts of Liabilities Presented in Statement of Condition Derivative Liability, Securities Sold under Agreements to Resell, and Securities Loaned Not Offset Against Collateral Derivative Liability, Securities Sold under Agreements to Resell, and Securities Loaned Not Offset Against Collateral Total derivatives and other financial instruments, Cash and Securities Provided Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash Total derivatives and other financial instruments, Net Amount Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Amount Offset Against Collateral Cash collateral received in connection to securities finance activities Securities Finance, Collateral, Obligation to Return Cash Securities Finance, Collateral, Obligation to Return Cash Securities lending, fair value, amount not offset against collateral Securities Lending, Fair Value, Amount Not Offset Against Collateral Securities Lending, Fair Value, Amount Not Offset Against Collateral Schedule of Short-term Debt Schedule of Short-term Debt [Table Text Block] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Non-U.S. Current Foreign Tax Expense (Benefit) Total current expense Current Income Tax Expense (Benefit) Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Non-U.S. Deferred Foreign Income Tax Expense (Benefit) Total deferred expense (benefit) Total income tax expense (benefit) Income Tax Expense (Benefit) Other Assets Other Assets Disclosure [Text Block] Income Taxes Income Tax Disclosure [Text Block] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Volatility Measurement Input, Option Volatility [Member] Fair Value, Measurements, Significant Unobservable Inputs [Axis] Fair Value, Measurements, Significant Unobservable Inputs [Axis] Fair Value, Measurements, Significant Unobservable Inputs [Axis] Fair Value, Measurements, Significant Unobservable Inputs [Domain] Fair Value, Measurements, Significant Unobservable Inputs [Domain] Fair Value, Measurements, Significant Unobservable Inputs [Domain] Significant Unobservable Inputs Readily Available Significant Unobservable Inputs Readily Available [Member] Significant Unobservable Inputs Readily Available [Member] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain]