Fair Value - Components of Net Gains on Sales of Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Realized gains on sales of loans	$ 102,517	$ 67,218	$ 189,350	$ 75,526
Change in unrealized gains on loans held for sale	23,353	(15,897)	19,177	(2,271)
Capitalized servicing rights	45,554	36,305	98,167	37,595
Provision for repurchases	(1,838)	(2,010)	(4,024)	(2,181)
Interest income	8,721	8,473	17,066	9,261
Other		114	0	(34)
Net gains on sales of loans	144,611	235,949	248,645	314,394
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances	194,123	374,277	376,199	683,758
Interest Rate Lock Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains on derivatives	37,969	(17,217)	36,363	41,404
Forward Sales Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains on derivatives	(63,956)	183,625	(99,812)	179,688
Loan Purchase Commitments [Member]
Components of Net Gains on Sales of Loans (Detail) [Line Items]
Net fair value gains on derivatives	$ (7,709)	$ (24,662)	$ (7,642)	$ (24,662)