Assets Acquired in FDIC-Assisted Acquisitions - Rollforward of Acquired Covered Loans Deterioration of Credit Quality (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Loans with Deterioration of Credit Quality [Member]	Dec. 31, 2012 Loans with Deterioration of Credit Quality [Member]	Dec. 31, 2013 Loans without Deterioration of Credit Quality [Member]	Dec. 31, 2012 Loans without Deterioration of Credit Quality [Member]
Covered Loans [Line Items]
Balance, beginning of year	$ 29,537	$ 25,493	$ 16,698		$ 282,737	$ 307,790	$ 228,602	$ 266,966
Change in estimate of cash flows, net of charge-offs or recoveries					35,306	(17,712)	13,471	1,376
Additions due to acquisitions	9,863					73,414		51,368
Other (loan payments, transfers, etc.)					(100,996)	(80,755)	(68,883)	(91,108)
Balance, end of year	$ 159,724	$ 65,441		$ 242,394	$ 217,047	$ 282,737	$ 173,190	$ 228,602