Business Combinations (Summary of FDIC Indemnification Asset) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	$ (10,029)	$ 10,224	$ (6,100)	$ 11,846
Additions from acquisitions	0	0	0	0
Additions from reimbursable expenses	649	934	731	2,509
Amortization	(92)	(1,206)	(193)	(2,466)
Changes in expected reimbursements from the FDIC for changes in expected credit losses	(2,200)	(4,317)	(5,747)	(8,310)
(Payments received from) provided to the FDIC	(57)	(2,206)	(420)	(150)
Balance at end of period	$ (11,729)	$ 3,429	$ (11,729)	$ 3,429