Loans and Asset Quality Information (Details 5) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011		Sep. 30, 2011
ASSET QUALITY DATA
Nonaccrual loans	$ 107,032		$ 115,038		$ 108,627
Foreclosed real estate - non-covered	38,065		37,023		32,673
Foreclosed real estate - covered	58,367		85,272		104,785
Total nonperforming assets	259,931		263,271		277,176
Non-covered nonperforming Assets
ASSET QUALITY DATA
Nonaccrual loans	69,413		73,566		75,013
Restructured loans - accruing	38,522		11,720		11,257
Accruing loans > 90 days past due
Total nonperforming loans	107,935		85,286		86,270
Foreclosed real estate - non-covered	38,065		37,023		32,673
Total nonperforming assets	146,000		122,309		118,943
Covered nonperforming Assets
ASSET QUALITY DATA
Nonaccrual loans	37,619	[1]	41,472	[1]	36,536	[1]
Restructured loans - accruing	17,945		14,218		16,912
Accruing loans > 90 days past due
Total nonperforming loans	55,564		55,690		53,448
Foreclosed real estate - covered	58,367		85,272		104,785
Total nonperforming assets	$ 113,931		$ 140,962		$ 158,233

[1] At September 30, 2012, December 31, 2011, and September 30, 2011, the contractual balance of the nonaccrual loans covered by FDIC loss share agreements was $67.9 million, $69.0 million, and $65 million, respectively.