Name:	us-gaap_FeesAndCommissionsMortgageBankingAndServicing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of expense during the period for co-broker fees paid for obtaining loans.

No definition available.

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

Income from contractual loan origination related fees net of co-broker fees.

No definition available.

Name:	wd_ContractualLoanOriginationFeesNet
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Income from the estimated fair value of the expected net future cash flows associated with the servicing of loans.

No definition available.

Name:	wd_FairValueOfExpectedFutureCashFlowsFromServicingRightsRecognizedAtCommitment
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Decrease in gains from mortgage banking gains due to the recognition at commitment of the fair value of expected guaranty obligations.

No definition available.

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

Amount of realized and unrealized gain (loss) on the sale and mark-to-market of loans and derivative instruments during the period.

No definition available.