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	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at beginning of the period	$ 1,124,615	$ 1,015,607
Purchases and originations of loans held for sale	5,633,936	3,583,548
Proceeds from sales of and payments on loans held for sale	(5,693,335)	(4,059,701)
Realized gains on sales of loans	61,379	86,833
Change in unrealized gains (losses) on loans held for sale	1,389	(4,176)
Interest income	11,728	8,345
Transfers from loans held for investment (3)	16,690	0
Other	(215)	0
Balance at end of the period	$ 1,156,187	$ 630,456

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

3 Months Ended

Mar. 31, 2015

Mar. 31, 2014

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

Balance at beginning of the period

$ 1,124,615us-gaap_LoansReceivableHeldForSaleAmount

$ 1,015,607us-gaap_LoansReceivableHeldForSaleAmount

Purchases and originations of loans held for sale

5,633,936us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale

3,583,548us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale

Proceeds from sales of and payments on loans held for sale

(5,693,335)us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale

(4,059,701)us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale

Realized gains on sales of loans

61,379us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale

86,833us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleGainLossOnSale

Change in unrealized gains (losses) on loans held for sale

1,389us-gaap_IncreaseDecreaseInMortgageLoansHeldForSale

(4,176)us-gaap_IncreaseDecreaseInMortgageLoansHeldForSale

Interest income

11,728us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages

8,345us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages

Transfers from loans held for investment (3)

16,690us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1

0us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1

Other

(215)wac_LoansReceivableHeldForSaleReconciliationToCashFlowOtherPeriodIncreaseDecrease

0wac_LoansReceivableHeldForSaleReconciliationToCashFlowOtherPeriodIncreaseDecrease

Balance at end of the period

$ 1,156,187us-gaap_LoansReceivableHeldForSaleAmount

$ 630,456us-gaap_LoansReceivableHeldForSaleAmount

- Definition

The increase (decrease) during the reporting period in the value of mortgage loans that are held with the intention to sell or be securitized in the near future.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

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-Name Accounting Standards Codification

-Glossary Investing Activities

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- 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)

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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

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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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

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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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- Definition

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

+ References

No definition available.

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