Residential Loans - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($) Contract	Dec. 31, 2014 USD ($) Contract
Mortgage Loans on Real Estate [Line Items]
Principal balance of loans sold during period	$ 2,740,000	$ 4,930,000
Carrying value	$ 3,286,480	$ 3,286,480	$ 3,398,573
Percentage of fixed-rate loans	91.00%	91.00%
Sequoia
Mortgage Loans on Real Estate [Line Items]
Carrying value	$ 1,237,114	$ 1,237,114	$ 1,474,386
Fixed-rate loans
Mortgage Loans on Real Estate [Line Items]
Weighted average coupon rate	4.06%	4.06%
Hybrid loans
Mortgage Loans on Real Estate [Line Items]
Weighted average coupon rate	3.30%	3.30%
Residential Loans at Fair Value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| Contract		1,682	2,273
Loan Principal	$ 876,000	$ 876,000	$ 1,300,000
Valuation adjustments	3,000	1,000
Loan pledged as collateral	848,000	$ 848,000
Residential Loans at Lower of Cost or Fair Value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| Contract		9	9
Loan Principal	2,000	$ 2,000	$ 2,000
Carrying value	1,458	1,458	1,488
Residential Loans at Lower of Cost or Fair Value \| Sequoia
Mortgage Loans on Real Estate [Line Items]
Carrying value	0	$ 0	$ 0
Residential Loans Held For Investment at Fair Value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| Contract		1,519	803
Loan Principal	1,130,000	$ 1,130,000	$ 566,000
Valuation adjustments	6,000	4,000
Carrying value	1,160,000	1,160,000
Principal balance of loans transferred	213,000	650,000
Fair value of loans transferred	215,000	662,000
Loan pledged as collateral	$ 1,020,000	$ 1,020,000
Weighted average original Fair Isaac Corporation (FICO) score	772	772
Weighted average original loan-to-value (LTV)	65.00%	65.00%
Residential Loans Held For Investment at Fair Value \| Sequoia
Mortgage Loans on Real Estate [Line Items]
Number of loans \| Contract		4,999	5,315
Weighted average original Fair Isaac Corporation (FICO) score	732	732
Weighted average original loan-to-value (LTV)	66.00%	66.00%
Loans held-for-investment, delinquent greater than 90 days	$ 66,000	$ 66,000	$ 73,000
Loans held-for-investment, in foreclosure	36,000	36,000	39,000
Valuation adjustments	2,000	5,000
Residential Loans Held for Investment
Mortgage Loans on Real Estate [Line Items]
Loan Principal	1,343,333	1,343,333	1,483,213
Carrying value	1,237,114	1,237,114	1,474,386
Unamortized premium, net	0	0	12,511
Allowance for loan losses	0	0	$ 21,338
Mortgage servicing rights
Mortgage Loans on Real Estate [Line Items]
Principal balance of mortgage servicing rights purchased from third-party originators		1,820,000
Residential Loans
Mortgage Loans on Real Estate [Line Items]
Principal value of loans purchased	$ 2,780,000	$ 5,180,000

Fair Value Of Loans Securitized During Period

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Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure

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- Definition

The weighted average FICO score for borrowers at the time loans were originated.

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Financing Receivable, Loan To Value Ratio

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Financing Receivables, Weighted Average Interest Rate

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Loans Receivable, Percentage Bearing Fixed Interest, Percentage Rate

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Principal Amount Of Loans Securitized During Period

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Principal Balance of Loans Acquired During Period

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Principal Balance of Loans Sold During Period

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- Definition

Servicing Asset at Amortized Cost, Additions, Acquired From Third Parties

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- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 310

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For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

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This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of consumer loans, including, but not limited to, mortgage, home equity, vehicles, credit card, installment, and lease financing. Excludes loans and leases covered under loss sharing agreements.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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- Definition

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.

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Indicates the number of mortgages under each classification.

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The total periodic movement (increases and decreases) in the carrying amount of mortgage loans on real estate.

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This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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