Covered Loans - Summary of FDIC Loss Sharing Asset (Detail) (USD $) In Thousands, unless otherwise specified					6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2014 Adjustments Not Reflected in Income [Member]	Jun. 30, 2013 Adjustments Not Reflected in Income [Member]	Jun. 30, 2014 Adjustments Reflected in Income [Member]	Jun. 30, 2013 Adjustments Reflected in Income [Member]
Covered Loans [Line Items]
Beginning balance	$ 51,431	$ 88,513	$ 100,391	$ 116,624
Cash received from FDIC					(20,306)	(13,098)
(Amortization) accretion							(15,988)	(3,782)
Loan expenses to be reimbursed					(103)	911
Higher (lower) loan loss expectations							(18)	95
Write-downs/(gain) on sale of other real estate							(1,807)	1,093
Recovery amounts due to FDIC								(1,243)
Other					1,140	(270)		61
Ending balance	$ 51,431	$ 88,513	$ 100,391	$ 116,624