Residential Loans at Fair Value - Reconciliation of the Changes in Residential Loans Held for Sale to the Amounts Presented in the Consolidated Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at beginning of the year	$ 1,015,607	$ 45,065	$ 0
Purchases and originations of loans held for sale	18,878,305	16,141,573	22,259
Proceeds from sales of and payments on loans held for sale	(19,177,179)	(15,452,196)	(15,985)
Realized gains on sales of loans	367,314	218,504	537
Interest income	40,051	32,625	16
Acquisition of S1L	0	0	37,972
Transfers from loans held for investment	0	5,183	0
Other	(895)	82	0
Balance at end of the year	$ 1,124,615	$ 1,015,607	$ 45,065

Residential Loans at Fair Value - Reconciliation of the Changes in Residential Loans Held for Sale to the Amounts Presented in the Consolidated Statements of Cash Flows (Detail) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]

Balance at beginning of the year

$ 1,015,607us-gaap_LoansReceivableHeldForSaleAmount

$ 45,065us-gaap_LoansReceivableHeldForSaleAmount

$ 0us-gaap_LoansReceivableHeldForSaleAmount

Purchases and originations of loans held for sale

18,878,305us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale

16,141,573us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale

22,259us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale

Proceeds from sales of and payments on loans held for sale

(19,177,179)us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale

(15,452,196)us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale

(15,985)us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale

Realized gains on sales of loans

367,314us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale

218,504us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale

537us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale

Interest income

40,051us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages

32,625us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages

16us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages

Acquisition of S1L

0wac_LoansReceivableHeldForSaleReconciliationToCashFlowAdditionsFromBusinessAcquisition

37,972wac_LoansReceivableHeldForSaleReconciliationToCashFlowAdditionsFromBusinessAcquisition

Transfers from loans held for investment

0us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1

5,183us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1

0us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1

Other

(895)wac_LoansReceivableHeldForSaleReconciliationToCashFlowOtherPeriodIncreaseDecrease

82wac_LoansReceivableHeldForSaleReconciliationToCashFlowOtherPeriodIncreaseDecrease

0wac_LoansReceivableHeldForSaleReconciliationToCashFlowOtherPeriodIncreaseDecrease

Balance at end of the year

$ 1,124,615us-gaap_LoansReceivableHeldForSaleAmount

$ 1,015,607us-gaap_LoansReceivableHeldForSaleAmount

$ 45,065us-gaap_LoansReceivableHeldForSaleAmount

- Definition

Interest and fee income from mortgage loans considered to be held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.1)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 9

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- Definition

The face amount of loans that will be sold to other entities.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

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- Definition

The aggregate amount of cash outflow for loans purchased and created with the intention to resell them in the near future.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

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-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3461-108585

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- Definition

The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

+ References

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- Definition

Reflects, by transferred financial asset type, the amount of sales proceeds in excess of or deficient from the sum of the carrying amounts of transferred financial assets plus transaction costs, including those transactions in which the seller/transferor has continuing involvement with the financial assets that have been transferred.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

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-Paragraph 3

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- Definition

Value of loans and leases held in the entity's portfolio transferred to loans and leases held-for-sale in noncash transactions.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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- Definition

Loans receivable held for sale reconciliation to cash flow additions from business acquisition.

+ References

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- Definition

Loans receivable held for sale reconciliation to cash flow other period increase decrease.

+ References

No definition available.

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