Goodwill and Other Intangible Assets - Schedule of Change in Loan Servicing Rights (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Transfers And Servicing [Abstract]
Balance at beginning of year	$ 19,984	$ 12,900	$ 12,491
Origination of loan servicing rights	13,265	12,039	4,483
Amortization expense	(7,181)	(4,955)	(4,074)
Balance at end of year	26,068	19,984	12,900
Balance at beginning of year	(3,046)	(2,670)	(1,163)
Impairment adjustment	2,542	(376)	(1,507)
Balance at end of year	(504)	(3,046)	(2,670)
Balance at end of year, net of valuation allowance	$ 25,564	$ 16,938	$ 10,230