Effect of Derivative Instruments on Consolidated Statements of Income and Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Included in Mortgage Banking Income	$ 7,465	$ 1,438
Treasury Options
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Included in Mortgage Banking Income	(10,224)	(120)
Eurodollar Futures
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Included in Mortgage Banking Income	(38)	(1,468)
Forward commitments to buy/sell loans/mortgage-backed securities
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Included in Mortgage Banking Income	$ 17,727	$ 3,026