Business Combinations (Summary Of FDIC Indemnification Asset) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2012
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	$ 137,681		$ 208,160	$ 344,251	$ 222,568
Additions from acquisitions	0	65,100	0	78,264
Additions from reimbursable expenses	3,062	5,669	10,922	18,646
Amortization	(1,763)	(1,139)	(5,884)	(3,919)
Changes in expected reimbursements from the FDIC for changes in expected credit losses	(12,742)	(16,579)	(65,477)	(46,343)
Payments received from the FDIC	(25,925)	(37,314)	(47,408)	(152,594)
Balance at end of period	$ 100,313	$ 238,305	$ 100,313	$ 238,305	$ 222,568