Fair Value of Financial Instruments - Schedule of Company's Reconciliation of Level 3 Assets (Detail) (USD $) In Thousands, unless otherwise specified				12 Months Ended
	Dec. 31, 2013 Unrealized Gains on Securities [Member]	Dec. 31, 2012 Unrealized Gains on Securities [Member]	Dec. 31, 2011 Unrealized Gains on Securities [Member]	Dec. 31, 2013 Impaired Loans Carried at Fair Value [Member]	Dec. 31, 2012 Impaired Loans Carried at Fair Value [Member]	Dec. 31, 2013 Other Real Estate Owned [Member]	Dec. 31, 2012 Other Real Estate Owned [Member]	Dec. 31, 2013 Purchased Non-Covered Loans [Member]	Dec. 31, 2013 Purchased Non-Covered Other Real Estate Owned [Member]	Dec. 31, 2013 Covered Loans [Member]	Dec. 31, 2012 Covered Loans [Member]	Dec. 31, 2013 Covered Other Real Estate Owned [Member]	Dec. 31, 2012 Covered Other Real Estate Owned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 2,000	$ 2,000	$ 2,000	$ 52,514	$ 70,296	$ 39,850	$ 50,301			$ 507,712	$ 571,489	$ 88,273	$ 78,617
Total gains (losses) included in net income						(5,883)	(11,843)					(3,280)	2,892
Purchases, sales, issuances, and settlements, net				(831)		(9,753)	(20,428)	448,753	4,276	(85,642)	(20,479)	(57,818)	(36,534)
Transfers in or out of Level 3							4,038					(13,115)
Asset reclassification, within Level 3				(9,137)	(17,782)	9,137	17,782			(31,833)	(43,298)	31,833	43,298
Ending balance	$ 2,000	$ 2,000	$ 2,000	$ 42,546	$ 52,514	$ 33,351	$ 39,850	$ 448,753	$ 4,276	$ 390,237	$ 507,712	$ 45,893	$ 88,273