Assets Acquired in FDIC-Assisted Acquisitions - Loan-by-Loan Basis Performance of Fair Value Adjustments (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 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)	$ 50,703	$ 16,210	$ 23,050
Adjustments needed where the Company's initial estimate of cash flows were overstated: (recorded through a provision for loan losses)	6,305	11,435	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)	10,141	3,242	4,610
Adjustments needed where the Company's initial estimate of cash flows were overstated: (recorded through a provision for loan losses)	$ 1,261	$ 2,287	$ 2,638