Receivable from FDIC for Loss Share Agreements (Changes in Receivable from FDIC) (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Receivable From FDIC For Loss Share Agreements [Roll Forward]
Balance at beginning of period	$ 410,351,000		$ 624,322,000		$ 539,511,000	[1]	$ 623,261,000
Additional receivable from acquisitions	0		(4,985,000)		0		135,300,000
Accretion of discounts and premiums, net	(36,289,000)		(11,344,000)		(44,541,000)		(21,110,000)
Receipt of payments from FDIC	(68,894,000)		(83,083,000)		(192,098,000)		(211,928,000)
Post-acquisition and other adjustments, net	8,810,000		(2,403,000)		11,106,000		(3,016,000)
Balance at June 30	313,978,000	[2]	522,507,000	[2]	313,978,000	[2]	522,507,000	[2]
Adjustments to acquisition gains	$ 0

[1] Derived from 2011 Annual Report on Form 10-K.

[2] Unaudited