Assets Acquired in FDIC-Assisted Acquisitions - Loan-by-Loan Basis Performance of Fair Value Adjustments (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Statement Of Partners Capital [Abstract]
Adjustments needed where the Company's initial estimate of cash flows were underestimated: (recorded with a reclassification from non-accretable difference to accretable discount)	$ 39,278	$ 8,189	$ 23,050
Adjustments needed where the Company's initial estimate of cash flows were overstated: (recorded through a provision for loan losses)	3,950	7,185	13,190
Adjustments needed where the Company's initial estimate of cash flows were underestimated: (recorded with a reclassification from non-accretable difference to accretable discount)	2,942	1,638	4,610
Adjustments needed where the Company's initial estimate of cash flows were overstated: (recorded through a provision for loan losses)	$ 790	$ 1,437	$ 2,638