Other Assets Acquired through Foreclosure - Changes in Other Assets Acquired through Foreclosure (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) Property	Dec. 31, 2014 USD ($) Property	Dec. 31, 2013 USD ($)
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Other Assets Acquired through Foreclosure Additions Due to Business Acquisition	$ 1,407		$ 5,622
Gains Losses On Transfers To Other Real Estate And Foreclosed Assets	$ 851	$ 100	900
Number of Real Estate Properties | Property	39	67
Balance, beginning of the period, Gross Balance	$ 71,421	$ 88,421	113,474
Transfers to other assets acquired through foreclosure, net, Gross Balance	28,566	13,777	24,911
Proceeds from sale of other real estate owned and repossessed assets, net, Gross Balance	(51,038)	(33,643)	(61,510)
Gains (losses), net, Gross Balance	2,628	2,866	5,924
Balance, end of period, Gross Balance	52,984	71,421	88,421
Balance, beginning of the period, Valuation Allowance	(14,271)	(21,702)	(36,227)
Proceeds from sale of other real estate owned and repossessed assets, net, Valuation Allowance	5,411	7,725	18,268
Valuation adjustments, net, Valuation Allowance	(182)	(294)	(3,743)
Balance, end of period, Valuation Allowance	(9,042)	(14,271)	(21,702)
Balance, beginning of the period, Net Balance	57,150	66,719	77,247
Transfers to other assets acquired through foreclosure, net, Net Balance	28,566	13,777	24,911
Proceeds from sale of other real estate owned and repossessed assets, net, Net Balance	(45,627)	(25,918)	(43,242)
Valuation adjustments of other repossessed assets, net	(182)	(294)	(3,743)
Gains (losses), net, Net Balance	2,628	2,866	5,924
Balance, end of period, Net Balance	$ 43,942	$ 57,150	$ 66,719