Loans - Changes in FDIC Loss-Share Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
FDIC Indemnification Assets
Balance, beginning of the period	$ 8,404	$ 20,687	$ 13,848	$ 32,757
Discount accretion of the present value at the acquisition dates	43	12	130	35
Effect of additional cash flows on covered loans (prospective recognition)	0	(4,500)	(4,072)	(8,460)
Decrease in the provision for losses on covered loans	0	0	0	(4,417)
Other reimbursable expenses	(238)	745	174	2,248
Reimbursements from the FDIC	(1,082)	(684)	(2,835)	(4,967)
Other	140	(80)	22	(1,016)
Balance, end of the period	$ 7,267	$ 16,180	$ 7,267	$ 16,180