Covered Assets and FDIC Loss-sharing Asset (Covered OREO at Carrying Value) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Balance, beginning of period			$ 51,019
Proceeds from sale of OREO property			(11,899)	(7,874)
Gain on sale of OREO			6,277	5,455
Total OREO, end of period	33,004		33,004
Covered Loans [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Balance, beginning of period	24,430	13,527	28,126	14,443
Covered real estate acquired through foreclosure	0	10,896	0	10,896
Transfers in	2,933	1,668	5,401	5,092
Additional OREO write-down	(533)	(99)	(2,038)	(113)
Proceeds from sale of OREO property	(10,356)	(4,122)	(18,381)	(11,081)
Gain on sale of OREO	2,605	2,369	5,971	5,002
Total OREO, end of period	$ 19,079	$ 24,239	$ 19,079	$ 24,239