Loans and Allowance for Loan Losses - Changes in Carrying Amount of Covered Acquired Loans and Accretable Yield for Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Covered Loans [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	$ 358,666	$ 515,823
Carrying Amount of Loans, Additions
Carrying Amount of Loans, Payments received, net	(33,087)	(189,987)
Carrying Amount of Loans, Accretion	5,557	32,830
Carrying Amount of Loans, Balance at end of period	331,136	358,666
Accretable Yield, Balance at beginning of period	122,715	115,594
Accretable Yield, Additions
Accretable Yield, Payments received, net	(568)	(1,298)
Accretable Yield, Accretion	(5,557)	(32,830)
Accretable Yield, Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions	4,754	(17,433)
Accretable Yield, Net transfers from (to) nonaccretable difference to accretable yield	6,264	58,682
Accretable Yield, Balance at end of period	127,608	122,715
Non-Covered [Member]
Financing Receivable, Impaired [Line Items]
Carrying Amount of Loans, Balance at beginning of period	68,075	141,201
Carrying Amount of Loans, Additions
Carrying Amount of Loans, Payments received, net	(16,129)	(116,187)
Carrying Amount of Loans, Accretion	14,551	43,061
Carrying Amount of Loans, Balance at end of period	66,497	68,075
Accretable Yield, Balance at beginning of period	131,370	203,186
Accretable Yield, Additions
Accretable Yield, Payments received, net	(9,591)	(47,330)
Accretable Yield, Accretion	(14,551)	(43,061)
Accretable Yield, Decrease in expected cash flows based on actual cash flows and changes in cash flow assumptions	(100)	3,894
Accretable Yield, Net transfers from (to) nonaccretable difference to accretable yield	8,934	14,681
Accretable Yield, Balance at end of period	$ 116,062	$ 131,370