Goodwill and Other Intangible Assets - Schedule of Change in Loan Servicing Rights (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Balance at beginning of year	$ 20,446	$ 26,068	$ 19,984
Origination of loan servicing rights	1,696	1,065	13,265
Amortization expense	(5,461)	(6,687)	(7,181)
Balance at end of year	16,681	20,446	26,068
Balance at beginning of year	(592)	(504)	(3,046)
Impairment adjustment	303	(88)	2,542
Balance at end of year	(289)	(592)	(504)
Balance at end of year, net of valuation allowance	$ 16,392	$ 19,854	$ 25,564