Fair Value - Components of Net Gains on Sales of Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Realized gains on sales of loans	$ 61,379	$ 86,833
Change in unrealized gains (losses) on loans held for sale	1,389	(4,176)
Capitalized servicing rights	72,301	52,613
Provision for repurchases	(2,025)us-gaap_ProvisionForOtherLosses	(2,186)us-gaap_ProvisionForOtherLosses
Interest income	11,728	8,345
Net gains on sales of loans	125,227us-gaap_GainLossOnSaleOfMortgageLoans	104,034us-gaap_GainLossOnSaleOfMortgageLoans
Interest Rate Lock Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains (losses) on derivatives	24,782	(1,606)
Forward Sales Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains (losses) on derivatives	(38,648)	(35,856)
Loan Purchase Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains (losses) on derivatives	$ (5,679)	$ 67

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

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The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

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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.

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

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Amount of expense related to other loss.

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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.

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Gain associated with capitalized servicing rights.

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No definition available.

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