Loans - Changes in FDIC Loss-Share Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
FDIC Indemnification Assets
Balance, beginning of the period	$ 7,608	$ 31,257	$ 13,848	$ 32,757
Discount accretion of the present value at the acquisition dates	44	12	87	23
Effect of additional cash flows on covered loans (prospective recognition)	0	(2,104)	(4,072)	(3,960)
Decrease in the provision for losses on covered loans	0	(4,417)	0	(4,417)
Other reimbursable expenses	314	990	412	1,503
Reimbursements from the FDIC	201	(2,859)	(1,753)	(4,283)
Other	237	(2,192)	(118)	(936)
Balance, end of the period	$ 8,404	$ 20,687	$ 8,404	$ 20,687