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

Net capital is equal to the net worth of the broker dealer, less certain items such as exchange memberships, carrying value of securities not readily marketable, haircuts on marketable securities in proprietary accounts, furniture and equipment and other illiquid assets as defined.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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

The amount of additional collateral required for the lender risk-sharing portfolio over a specified period.

No definition available.

Name:	wd_AdditionalCollateralRequirementOfLenderOverSpecifiedPeriod
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The percentage of collateral requirements for the lender risk-sharing portfolio.

No definition available.

Name:	wd_CollateralRequirementsPercentage
Namespace Prefix:	wd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The minimum liquid assets required to be maintained by the entity to meet operational liquidity requirements as of the balance sheet date.

No definition available.

Name:	wd_MinimumLiquidAssetsRequiredToMeetOperationalLiquidityRequirements
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the net worth (total assets minus total liabilities) required to be maintained by the entity.

No definition available.

Name:	wd_NetWorthRequirement
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The operational liquidity of the entity as of the balance sheet date.

No definition available.

Name:	wd_OperationalLiquidity
Namespace Prefix:	wd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The period over which the collateral requirement for loans will be funded.

No definition available.

Name:	wd_PeriodForFundingCollateralRequirement
Namespace Prefix:	wd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The percentage of the restricted liquidity collateral haircut.

No definition available.

Name:	wd_RestrictedLiquidityCollateralHaircutPercentage
Namespace Prefix:	wd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=wd_RiskSharingObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LineOfCreditFacilityAxis=wd_FannieMaeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=wd_TierTwoMortgageLoansNewMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: