Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
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Data Type:	xbrli:stringItemType
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Period Type:	duration

This is the principal amount of loans (across all types of loans) that are overdue in payment by a set number of days.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Name:	us-gaap_DelinquentAmountAtEndOfPeriodOnLoansManagedAndSecuritized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Period Type:	instant

Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease.

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Namespace Prefix:	us-gaap_
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Amortized cost excluding accrued interest of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)

Name:	us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of unamortized loan commitment, origination, and other costs (fees) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

Name:	us-gaap_FinancingReceivableUnamortizedLoanFeeCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

This is the result of the principal amount outstanding of total loans managed or securitized less securitized loans and loans that are in the process of being securitized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

Name:	us-gaap_PrincipalAmountOutstandingOfLoansHeldInPortfolio
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of specific reserve for financial receivables.

No definition available.

Name:	wd_FinancingReceivableSpecificReserve
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of loans that are considered delinquent (past due) at the end of the period.

No definition available.

Name:	wd_NumberOfDelinquentLoans
Namespace Prefix:	wd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of real estate loans held for investment.

No definition available.

Name:	wd_NumberOfLoansHeldForInvestment
Namespace Prefix:	wd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of loans on nonaccrual status at the end of the period.

No definition available.