Business Combinations (Summary of FDIC Indemnification Asset) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	$ 0	$ 11,846
Balance at beginning of period, Liability	(6,100)
Additions from acquisitions	0	0
Additions from reimbursable expenses	82	1,575
Amortization	(101)	(1,260)
Changes in expected reimbursements from the FDIC for changes in expected credit losses	(3,547)	(3,993)
(Payments received from) provided to the FDIC	(363)	2,056
Balance at end of period	0	$ 10,224
Balance at end of period, Liability	$ (10,029)