Fair Value Disclosures [Abstract] Carrying amounts and fair values of financial instruments measured based on level two inputs Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Real Estate [Abstract] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Market At Mill Creek Partners, LLC Market At Mill Creek Partners, LLC [Member] Market At Mill Creek Partners, LLC [Member] Brooks Crossing Brooks Crossing [Member] Brooks Crossing. Wills Wharf, Baltimore, Maryland Wills Wharf, Baltimore, Maryland [Member] Wills Wharf, Baltimore, Maryland [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Indian Lakes Crossing Indian Lakes Crossing [Member] Indian Lakes Crossing [Member] Parkway Centre Parkway Centre [Member] Parkway Centre [Member] Lexington Square Lexington Square [Member] Lexington Square [Member] Indian Lakes Crossing, Parkway Centre, and Lexington Square Indian Lakes Crossing, Parkway Centre, And Lexington Square [Member] Indian Lakes Crossing, Parkway Centre, And Lexington Square [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Chesterfield, Virginia Chesterfield, Virginia [Member] Chesterfield, Virginia [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Consideration transferred Business Combination, Consideration Transferred Capitalized acquisition costs Capitalized Acquisition Costs Capitalized Acquisition Costs Acquisition, cash consideration Payments to Acquire Businesses, Gross Acquisition, equity consideration issued or issuable Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Length of additional consideration contingency Business Combination, Length Of Additional Consideration Contingency Business Combination, Length Of Additional Consideration Contingency Number of operating properties acquired Number Of Operating Properties Acquired Number Of Operating Properties Acquired Payments to acquire land Payments to Acquire Land Ownership interest in partnership Percentage Of Ownership In Partnership Percentage Of Ownership In Partnership Investment in project Payments to Acquire Interest in Subsidiaries and Affiliates Term of contract Lessee, Operating Lease, Term of Contract Number of renewal terms Lessee, Operating Lease, Number Of Renewal Terms Lessee, Operating Lease, Number Of Renewal Terms Renewal term Lessee, Operating Lease, Extension Term Lessee, Operating Lease, Extension Term Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Site improvements Land Improvements [Member] Building and improvements Building and Building Improvements [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] In-place leases Leases, Acquired-in-Place [Member] Above-market leases Leases, Acquired-in-Place, Market Adjustment [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Property, plant, and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Finite-lived intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Below-market leases Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Below-Market Leases Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Below-Market Leases Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Fair Value of Financial Instruments Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Indebtedness Long-term Debt, Fair Value Notes receivable Notes Receivable, Fair Value Disclosure Interest rate swap liabilities Interest Rate Derivative Liabilities, at Fair Value Interest rate swap and cap assets Interest Rate Derivative Assets, at Fair Value Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of derivatives Schedule of Derivative Instruments [Table Text Block] Schedule of changes in fair value of derivatives Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Real estate investments: Real Estate Investment Property, Net [Abstract] Income producing property Rental Properties Held for development Land Available for Development Construction in progress Construction in Progress, Gross Gross real estate investments Real Estate Investment Property, at Cost Accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Net real estate investments Real Estate Investment Property, Net Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents Accounts receivable, net Accounts Receivable, Net Notes receivable Financing Receivable, Gross Construction receivables, including retentions Contract Receivable Including Retainage Amount billed to customers under long-term contracts or programs but not paid. Includes amounts due that have been withheld because of retainage provisions in a contract. Construction contract costs and estimated earnings in excess of billings Costs in Excess of Billings Equity method investments Equity Method Investments Other assets Other Assets Total Assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Indebtedness, net Long-term Debt Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities Construction payables, including retentions Construction Payable Billings in excess of construction contract costs and estimated earnings Billings in Excess of Cost Other liabilities Other Liabilities Total Liabilities Liabilities Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.01 par value, 100,000,000 shares authorized, none issued and outstanding as of September 30, 2018 and December 31, 2017 Preferred Stock, Value, Issued Common stock, $0.01 par value, 500,000,000 shares authorized, 49,576,222 and 44,937,763 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Distributions in excess of earnings Accumulated Distributions in Excess of Net Income Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total Liabilities and Equity Liabilities and Equity Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Accounting Policies [Abstract] Schedule of restricted cash Restrictions on Cash and Cash Equivalents [Table Text Block] Summary of changes due to new accounting principle Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] General contracting and real estate services General Contracting And Real Estate Services [Member] General Contracting And Real Estate Services [Member] Statement [Line Items] Statement [Line Items] General contracting and real estate services revenues Revenue from Contract with Customer, Excluding Assessed Tax General contracting and real estate services expenses Cost of Goods and Services Sold Revenues Revenues [Abstract] Rental revenues Operating Leases, Income Statement, Lease Revenue Total revenues Revenues Expenses Cost of Revenue [Abstract] Rental expenses Direct Costs of Leased and Rented Property or Equipment Real estate taxes Real Estate Tax Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction General and administrative expenses General and Administrative Expense Acquisition, development and other pursuit costs Acquisition Development And Other Pursuit Costs Acquisition Development And Other Pursuit Costs Impairment charges Asset Impairment Charges Total expenses Operating Expenses Operating income Operating Income (Loss) Interest income Interest Income (Expense), Nonoperating, Net Interest expense Interest Expense Loss on extinguishment of debt Gain (Loss) on Extinguishment of Debt Gain on real estate dispositions Gains on Dispositions and Acquisition of Real Estate Gains on dispositions and acquisition of real estate. Change in fair value of interest rate derivatives Derivative, Gain (Loss) on Derivative, Net Other income Other Nonoperating Income (Expense) Income before taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax benefit (provision) Income Tax Expense (Benefit) Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to stockholders Net Income (Loss) Attributable to Parent Net income attributable to stockholders per share (basic and diluted) (in dollars per share) Earnings Per Share, Basic and Diluted Weighted-average common shares outstanding (basic and diluted) (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Dividends and distributions declared per common share and unit (in dollars per share) Common Stock, Dividends, Per Share, Declared Comprehensive income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Net income Unrealized cash flow hedge losses Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Realized cash flow hedge losses reclassified to net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Equity [Abstract] Equity Stockholders' Equity Note Disclosure [Text Block] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Wawa Outparcel Wawa Outparcel [Member] Wawa Outparcel [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Contract price Proceeds from Sale of Real Estate Held-for-investment Gain (loss) on disposal Gain (Loss) on Sale of Properties, before Applicable Income Taxes Organization, Consolidation and Presentation of Financial Statements [Abstract] Business of Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Operating Partnership Operating Partnership [Member] Operating partnership. Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Financial Guarantee Financial Guarantee [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter of Credit Letter of Credit [Member] 1405 Point Point Street Apartments Baltimore Maryland [Member] Represents information pertaining to the Point Street Apartments located in Baltimore, Maryland. Commitments and Contingencies Loss Contingencies [Line Items] Line of credit, performance and payment bonds Contractual Obligation Credit facility, amount outstanding Letters of Credit Outstanding, Amount Credit facility, amount outstanding Long-term Line of Credit Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Indebtedness Debt Disclosure [Text Block] Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] City Center Durham City Center II LLC [Member] Durham City Center II LLC [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] 22-Story Mixed Use Tower Twenty Two Story Mixed Use Tower [Member] Twenty Two Story Mixed Use Tower [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Interests in equity method investments Equity Method Investment, Ownership Percentage Number stories in the mixed use tower (story) Number Of Stories In Property Number Of Stories In Property Investment in equity method investment during period Payments to Acquire Equity Method Investments Investment in equity method investments Investment In Equity Method Investments Investment In Equity Method Investments Guarantee of construction loan Guarantee Percentage Of Construction Loan Guarantee Percentage Of Construction Loan Assets being used as collateral for the construction loan Percentage Of Assets Used As Collateral For Construction Loan Percentage Of Assets Used As Collateral For Construction Loan Construction loan outstanding Dividends from equity investment Proceeds from Equity Method Investment, Distribution Income from equity method investment Income (Loss) from Equity Method Investments 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 operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation of buildings and tenant improvements Depreciation Amortization of leasing costs and in-place lease intangibles Amortization Of Leasing Costs And In-Place Lease Intangibles Represents the amortization of leasing costs and in-place lease intangibles. Accrued straight-line rental revenue Straight Line Rent Amortization of leasing incentives and above or below-market rents Amortization Of Lease Incentives And Above And Below Market Rents Amortization of lease incentives and above and below market rents. Accrued straight-line ground rent expense Amortization Of Ground Leases Amortization of long-term land leases capitalized as part of real property. Bad debt expense Provision for Doubtful Accounts Noncash stock compensation Share-based Compensation Noncash interest expense Amortization of Debt Issuance Costs and Discounts Loss on extinguishment of debt Gain on real estate dispositions Gain (Loss) on Disposition of Assets Change in the fair value of interest rate derivatives Unrealized Gain (Loss) on Derivatives Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Property assets Increase (Decrease) in Other Operating Assets Property liabilities Increase (Decrease) in Other Operating Liabilities Construction assets Increase (Decrease) in Contract with Customer, Asset Construction liabilities Increase (Decrease) in Contract with Customer, Liability Interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Development of real estate investments Payments to Develop Real Estate Assets Tenant and building improvements Payments for Tenant Improvements Acquisitions of real estate investments, net of cash received Payments to Acquire Businesses, Net of Cash Acquired Dispositions of real estate investments, net of selling costs Notes receivable issuances Payments to Acquire Notes Receivable Leasing costs Payments for Leasing Costs Leasing incentives Increase Decrease In Deferred Lease Incentives Increase decrease in deferred lease incentives. Contributions to equity method investments Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from sales of common stock Proceeds from Issuance of Common Stock Offering costs Payments of Stock Issuance Costs Common shares tendered for tax withholding Payments Related to Tax Withholding for Share-based Compensation Debt issuances, credit facility and construction loan borrowings Proceeds from Issuance of Debt Debt and credit facility repayments, including principal amortization Repayments of Debt Debt issuance costs Payments of Debt Issuance Costs Redemption of operating partnership units Payments for Repurchase of Redeemable Noncontrolling Interest Dividends and distributions Payments of Dividends Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including 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 Supplemental Disclosures (noncash transactions): Supplemental Cash Flow Information [Abstract] Increase in dividends payable Change In Dividends Payable Change In Dividends Payable Increase (decrease) in accounts payable and accrued liabilities for capital expenditures Change In Capital Expenditures Incurred But Not Yet Paid Change In Capital Expenditures Incurred But Not Yet Paid Issuance of operating partnership units for acquisitions Common Stock Or Units Issued For Acquisition Value The fair value of noncash common stock and/or operating partnership units issued as part of real estate acquisitions. Operating Partnership units redeemed for common shares Conversion of Stock, Amount Converted Redeemable noncontrolling interest from development Temporary Equity, Stock Issued During Period, Value, New Issues Deferred payment for land acquisition Payments to Acquire Businesses, Deferred Payments to Acquire Businesses, Deferred Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Receivables [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Mezzanine Loan Mezzanine Loan [Member] Mezzanine Loan [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] The Residences at Annapolis Junction The Residences At Annapolis Junction [Member] The Residences At Annapolis Junction Shopping Center in Summerville, South Carolina Shopping Center In Summerville, South Carolina [Member] Shopping Center In Summerville, South Carolina [Member] North Decatur Square North Decatur Square [Member] North Decatur Square [Member] The Interlock In West Midtown Atlanta The Interlock In West Midtown Atlanta [Member] The Interlock In West Midtown Atlanta [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Construction loans Construction Loans [Member] Bridge loan Bridge Loan [Member] Beatty Development Group Beatty Development Group [Member] Represents information pertaining to Beattly Development Group (BDG). AJAO Annapolis Junction Apartments Owner LLC [Member] Annapolis Junction Apartments Owner LLC [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Guarantor obligations, maximum exposure (up to) Guarantor Obligations, Maximum Exposure, Undiscounted Purchase option, percentage of development Purchase Option Percentage of Development The percentage of the development project that may be purchased by the Company. Maximum loan commitment Financing Receivable, Maximum Commitment The maximum amount available to the borrower under the loan commitment. Interest rate Financing Receivable, Interest Rate, Stated Percentage Financing Receivable, Interest Rate, Stated Percentage Additional advances Financing Receivable, Cash Advanced Financing Receivable, Cash Advanced Purchase option, selling price Purchase Option, Selling Price Purchase Option, Selling Price Expiration period Line of Credit Facility, Expiration Period Duration of extension option Line Of Credit Facility, Duration Of Extension Option Line Of Credit Facility, Duration Of Extension Option Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Construction Contracts Construction Contracts [Member] Real Estate Service Fees Real Estate Service Fees [Member] Real Estate Service Fees [Member] Cost Reimbursements Cost Reimbursements [Member] Cost Reimbursements [Member] Tax Protection Agreements Tax Protection Agreements [Member] Represents information pertaining to related party tax protection agreements that indemnify certain directors and executive officers from tax liabilities resulting from the potential future sale of certain properties within a specified period of completion of the formation transactions. Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Executive Officers Executive Officer [Member] Related Party Transactions Related Party Transaction [Line Items] Revenue from contracts with affiliated entities Revenue from Related Parties Gross profit from related parties Gross Profit from Related Parties Amount of gross profit between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates. Future sale period for properties Future Sale Period for Properties Period during which certain directors and executive officers will be protected from their tax liabilities resulting from potential future sales of property Future sale period for properties in limited number of cases Future Sale Period for Properties in Limited Number of Cases Future sale period for properties in limited number of cases. Period of opportunity to guarantee debt Period Of Opportunity to Guarantee Debt Represents the period of opportunity to guarantee debt, or enter into a deficit restoration obligation from the closing of the entity's initial public offering. Guarantee of debt Related Party Guarantee On Outstanding Debt Represents the amount of outstanding debt of the entity guaranteed by the related party. Real Estate Investment Real Estate Disclosure [Text Block] Segment Reporting [Abstract] Segments Segment Reporting Disclosure [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 Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Ex Transition Period Entity Ex Transition Period Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Statement of Stockholders' Equity [Abstract] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional paid-in capital Additional Paid-in Capital [Member] Distributions in excess of earnings Accumulated Distributions in Excess of Net Income [Member] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] Total stockholders' equity Parent [Member] Noncontrolling interests Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (in shares) Common Stock, Shares, Outstanding Beginning balance Net proceeds from sales of common stock (in shares) Stock Issued During Period, Shares, New Issues Net proceeds from sales of common stock Stock Issued During Period, Value, New Issues Restricted stock awards, net of tax withholding (in shares) Restricted Stock, Shares Issued Net of Shares for Tax Withholdings Restricted stock awards, net of tax withholding Restricted Stock, Value, Shares Issued Net of Tax Withholdings Restricted stock award forfeitures (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Restricted stock award forfeitures Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Issuance of operating partnership units for acquisitions Partners' Capital Account, Acquisitions Redemption of operating partnership units (in shares) Partners' Capital Account, Units, Redeemed Redemption of operating partnership units Partners' Capital Account, Redemptions Dividends and distributions declared Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Ending balance, shares (in shares) Ending balance Contractors [Abstract] Summary of balances and changes of construction contracts Contract with Customer, Asset and Liability [Table Text Block] Net position of uncompleted construction contracts Net Position of Cost and Estimated Earning on Uncompleted Contracts Table [Text Block] Net Position of Cost and Estimated Earning on Uncompleted Contracts Table [Text Block] Net operating income of reportable segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Reconciliation of net operating income to net income Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Construction Contracts Long-term Contracts or Programs Disclosure [Text Block] Notes Receivable Financing Receivables [Text Block] Change In Contract With Customer, Asset [Roll Forward] Change In Contract With Customer, Asset [Roll Forward] Change In Contract With Customer, Asset [Roll Forward] Balance as of January 1, 2018 Contract with Customer, Asset, Net Transferred to receivables Contract with Customer, Asset, Reclassified to Receivable Construction contract costs and estimated earnings not billed during the period Contract With Customer, Asset, Costs And Earnings Not Billed Contract With Customer, Asset, Costs And Earnings Not Billed Changes due to cumulative catch-up adjustment arising from changes in the estimate of the stage of completion Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress Balance as of September 30, 2018 Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Balance as of January 1, 2018 Contract with Customer, Liability Revenue recognized that was included in the balance at the beginning of the period Contract with Customer, Liability, Revenue Recognized Increases due to new billings, excluding amounts recognized as revenue during the period Contract With Customer, Liability, Increase From Billings Contract With Customer, Liability, Increase From Billings Changes due to cumulative catch-up adjustment arising from changes in the estimate of the stage of completion Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress Balance as of September 30, 2018 Business And Organization [Table] Business And Organization [Table] Schedule for business and organization. Partner Type [Axis] Partner Type [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] General Partner General Partner [Member] Operating Property Operating Property [Member] Operating Property [Member] Development Property Development Property [Member] Development Property [Member] Business And Organization [Line Items] Business And Organization [Line Items] Line items for business and organization. Percentage of Operating Partnership held Percentage Of Ownership Interests In Operating Partnership Percentage of ownership interests in operating partnership. Number of real estate properties Number of Real Estate Properties Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Change In Interest Rate [Axis] Change In Interest Rate Terms [Axis] Change In Interest Rate Terms [Axis] Change In Interest Rate [Domain] Change In Interest Rate [Domain] [Domain] for Change In Interest Rate [Axis] Stabilization of property Stabilization Of Property [Member] Stabilization Of Property [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Initial tranche Initial Tranche [Member] Initial Tranche [Member] New Credit Facility New Credit Facility [Member] Represents the senior unsecured credit facility. Secured Debt Secured Debt [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Revolving Credit Facility Revolving Credit Facility [Member] Term Loan Facility Senior Unsecured Term Loan Facility [Member] Senior Unsecured Term Loan Facility [Member] Line of credit Line of Credit [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Sandbridge Commons Sandbridge Commons [Member] Sandbridge Commons [Member] Columbus Village Columbus Village [Member] Represents the detail pertaining to Columbus Village. Southgate Square Southgate Square [Member] Southgate Square [Member] River City River City [Member] River City [Member] 249 Central Park Retail 249 Central Park Retail, Fountain Plaza Retail, And South Retail [Member] 249 Central Park Retail, Fountain Plaza Retail, And South Retail [Member] Market at Mill Creek Market At Mill Creek [Member] Market At Mill Creek [Member] Johns Hopkins Village Johns Hopkins Village [Member] Johns Hopkins village. Lightfoot Marketplace Lightfoot Marketplace [Member] Lightfoot Marketplace [Member] Indebtedness Debt Instrument [Line Items] Aggregate capacity under the credit facility Proceeds from lines of credit Proceeds from Lines of Credit Accordion feature maximum borrowing capacity Line Of Credit Facility, Accordion Feature, Maximum Borrowing Capacity Line Of Credit Facility, Accordion Feature, Maximum Borrowing Capacity Number of extension options Line Of Credit Facility, Number Of Extension Options Line Of Credit Facility, Number Of Extension Options Extension fee percentage Line Of Credit Facility, Extension Fee Percentage Line Of Credit Facility, Extension Fee Percentage Stated interest rate, basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Basis points on unused commitment fee Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Interest rate on credit facility as of end of period Line of Credit Facility, Interest Rate at Period End Increase in borrowing Line of Credit Facility, Increase (Decrease), Net Repayment of debt Repayments of Long-term Debt Face amount Debt Instrument, Face Amount Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Interest rate Debt Instrument, Interest Rate, Stated Percentage Borrowings under construction loans Proceeds from Construction Loans Payable Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share 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 dollars 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) Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Costs incurred on uncompleted construction contracts Costs on Uncompleted Contracts Costs On Uncompleted Contracts Estimated earnings Estimated Earnings On Uncompleted Contracts Estimated Earnings On Uncompleted Contracts Billings Billed Construction Contracts Amount billed for construction contracts as of the balance sheet date. Net position Uncompleted Contracts Net Assets Net contract asset (liability) position of uncompleted contracts Billings in excess of construction contract costs and estimated earnings Basis of Presentation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] General Contracting and Real Estate Services Revenues Revenue from Contract with Customer [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Segments Segment Reporting, Policy [Policy Text Block] Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value Measurement, Policy [Policy Text Block] Legal Proceedings Commitments and Contingencies, Policy [Policy Text Block] Delray Plaza Delray Plaza [Member] Delray Plaza [Member] Nexton Square Nexton Square [Member] Nexton Square [Member] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as accounting hedge Designated as Hedging Instrument [Member] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] Restatement Adjustment Restatement Adjustment [Member] Adjustments for Error Corrections [Axis] Adjustments for Error Corrections [Axis] Adjustments for Error Correction [Domain] Adjustments for Error Correction [Domain] Reclassification Of Earned Interest Income Reclassification Of Earned Interest Income [Member] Reclassification Of Earned Interest Income [Member] Reclassification For Shares Tendered For Tax Withholding Reclassification For Shares Tendered For Tax Withholding [Member] Reclassification For Shares Tendered For Tax Withholding [Member] Error Corrections and Prior Period Adjustments Restatement [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Interest receivable Notes receivable issuances Common shares tendered for tax withholding Summary of Mezzanine Loans Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Summary of Interest Income Interest and Other Income [Table Text Block] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Segment Reconciling Items Segment Reconciling Items [Member] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Gross profit Gross Profit Depreciation and amortization General and administrative expenses Acquisition, development and other pursuit costs Impairment charges Gain on real estate dispositions Other income Income tax benefit (provision) Equity Method Investment Equity Method Investments and Joint Ventures Disclosure [Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Construction receivables retentions Contract Receivable Retainage Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Capitalized Contract Cost [Axis] Capitalized Contract Cost [Axis] Capitalized Contract Cost [Domain] Capitalized Contract Cost [Domain] Portion Attributable To Pending Contracts Portion Attributable To Pending Contracts [Member] Portion Attributable To Pending Contracts [Member] Construction Construction [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Deferred pre-contract costs Capitalized Contract Cost, Net Retention payable Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-15 Accounting Standards Update 2016-15 [Member] Activities as originally presented Previously Reported [Member] Adjustment relating to restricted cash Adjustment Relating To Restricted Cash [Member] Adjustment Relating To Restricted Cash [Member] Adjustment for shares tendered for tax withholding Adjustment For Shares Tendered For Tax Withholding [Member] Adjustment For Shares Tendered For Tax Withholding [Member] Adjustment relating to interest income presentation Adjustment Relating To Interest Income Presentation [Member] Adjustment Relating To Interest Income Presentation [Member] Net cash provided by operating activities Net cash used for investing activities Net cash provided by (used in) financing activities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] General contracting and real estate services General Contracting And Real Estate Services Segment [Member] Represents information pertaining to General Contracting and Real Estate Services segment. Intercompany Eliminations Intersegment Eliminations [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] General and Administrative Expense General and Administrative Expense [Member] Segment Reporting Information Segment Reporting Information [Line Items] Non-cash stock compensation Derivative [Table] Derivative [Table] Not designated as accounting hedges Not Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Caps Interest Rate Cap [Member] Interest Rate Swaps Interest Rate Swap [Member] Derivatives Derivative [Line Items] Interest rate agreement, notional amount Derivative, Notional Amount Strike rate Derivative, Cap Interest Rate Interest rate cap agreement, premium (less than) Premiums Paid On Derivative Instruments Premiums paid on derivative instruments. Fixed interest rate Derivative, Fixed Interest Rate Unrealized losses Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss) Realized gain (loss) reclassified to earnings Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Gain (loss) reclassified during next 12 months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] New ATM Program At-the-Market Continuous Equity Program [Member] Represents at-the market continuous equity program through which the entity may issue and sell common stock. Capital Units by Class [Axis] Capital Units by Class [Axis] Capital Unit, Class [Domain] Capital Unit, Class [Domain] Class A units Capital Unit, Class A [Member] Class B units Capital Unit, Class B [Member] Class C units Capital Unit Class C [Member] Class C of capital units, which are a type of ownership interest in a corporation. Consolidation Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Consolidated Entities Under Development Or Construction Consolidated Entities Under Development Or Construction [Member] Consolidated Entities Under Development Or Construction [Member] Class of Stock Class of Stock [Line Items] Maximum aggregate offering price of shares to be sold (up to) Maximum Value of Shares Available To Be Issued Represents the maximum aggregate offering prices of shares available to be issued. Shares issued (in shares) Weighted average price (in dollars per share) Sale of Stock, Price Per Share Consideration received on transaction Sale of Stock, Consideration Received on Transaction Authorized capital shares of common stock (in shares) Authorized capital shares of preferred stock (in shares) Preferred stock issued (in shares) Preferred stock outstanding (in shares) Class A Units not held by Company (in shares) Units Not Held By Company Represents the number of units not held by the Company. Ownership interest percentage in properties Nonredeemable Noncontrolling Interest Acquisition, common units/shares issued or to be issued (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Units redeemed (in shares) Payments for redemption of partnership units Payments For Redemption Of Partnership Units Payments For Redemption Of Partnership Units Aggregate cash dividends and distributions, paid Summary of the purchase price allocation Schedule of Business Acquisitions, by Acquisition [Table Text Block] Revenue, Remaining Performance Obligation [Roll Forward] Revenue, Remaining Performance Obligation [Roll Forward] Revenue, Remaining Performance Obligation [Roll Forward] Beginning backlog Revenue, Remaining Performance Obligation, Amount New contracts/change orders Revenue, Remaining Performance Obligation, New Or Modified Contracts Revenue, Remaining Performance Obligation, New Or Modified Contracts Work performed Revenue, Remaining Performance Obligation, Work Performed Revenue, Remaining Performance Obligation, Work Performed Ending backlog Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Expected completion of contracts Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 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] Amended and Restated 2013 Equity Incentive Plan Amended and Restated 2013 Equity Incentive Plan [Member] Amended and Restated 2013 Equity Incentive Plan [Member] Long Term Incentive Plan Long Term Incentive Plan [Member] Represents information pertaining to the Long Term Incentive Plan ("LTIP"). Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Restricted Stock [Member] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Grant Date Share-based Compensation Award, Tranche One [Member] First Anniversary Share-based Compensation Award, Tranche Two [Member] Second Anniversary Share-based Compensation Award, Tranche Three [Member] Share-based Compensation Arrangement by Share-based Payment Award Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of additional shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Number of shares reserved for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Shares available for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Restricted stock granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Restricted stock granted, grant date fair value (in dollars 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 Employee restricted stock award, vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Restricted stock award, vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Non-employee restricted stock award vest grant over period Share Based Compensation Arrangement By Share Based Payment Award, Award Vesting Period For Nonemployee Directors Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period For Nonemployee Directors Performance period Share Based Compensation Arrangement by Share Based Payment Award, Performance Period The number of years in the performance period for the purpose of setting performance goals for a share-based compensation plan. Service period Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Stock-based compensation expense Allocated Share-based Compensation Expense Nonvested restricted shares outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Unrecognized compensation cost, recognition period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Interest rate swaps Interest rate caps Notional Amount Asset, Fair Value Derivative Asset, Fair Value, Gross Asset Liability, Fair Value Derivative Liability, Fair Value, Gross Liability Change in fair value of interest rate derivatives Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Total change in fair value of interest rate derivatives Derivative, Change In Fair Value, Gain (Loss) The change in fair value of derivatives, including derivatives designated as accounting hedges and derivatives not designated as accounting hedges. Office real estate Office Real Estate Segment [Member] Represents information pertaining to Office Real Estate segment. Retail real estate Retail Real Estate Segment [Member] Represents information pertaining to Retail Real Estate segment. Multifamily residential real estate Multifamily [Member] Segment revenues Segment expenses Gross profit Cash, cash equivalents, and restricted cash