Noninterest Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Noninterest Expense [Abstract]
Employee compensation and benefits	$ 42,436	$ 47,381
OREO operations	2,030	1,992
Occupancy and equipment	9,859	10,287
Data processing	6,577	6,430
FDIC insurance	1,930	1,856
Professional Fees	5,952	2,989
Depreciation	2,934	2,913
Advertising	2,436	3,154
Travel and entertainment	1,171	1,064
Merger and acquisition	1,036	6,135
Amortization of other intangible assets	1,659	1,405
Other	3,909	3,043
Total noninterest expense	$ 81,929	$ 88,649