Acquired Loans (Detail) - Changes in FDIC Indemnification Asset (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
FDIC Indemnification Asset [Roll Forward]
Balance at the beginning of the year	$ 37,051	$ 65,609	$ 95,899
Amortization	(2,984)	(14,098)	(11,495)
Change in expected reimbursements from the FDIC for changes in expected credit losses	(1,242)	3,338	39,096
Payments received from the FDIC	(16,240)	(17,798)	(57,891)
Balance at the end of the year	$ 16,585	$ 37,051	$ 65,609