Noninterest Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Noninterest Expense [Abstract]
Employee compensation and benefits	$ 45,803	$ 46,485	$ 88,239	$ 93,866
OREO operations	2,549	3,337	4,579	5,329
Occupancy and equipment	9,567	10,932	19,426	21,219
Data processing	6,471	7,033	13,048	13,463
FDIC insurance	1,634	1,989	3,564	3,846
Professional Fees	2,985	4,800	8,937	7,789
Depreciation	3,058	2,923	5,992	5,836
Advertising	1,759	3,774	4,195	6,928
Travel and entertainment	1,513	1,535	2,684	2,599
Merger and acquisition	2,268	2,262	3,304	8,397
Amortization of other intangible assets	1,711	1,791	3,370	3,196
Other	2,360	746	6,269	3,788
Total noninterest expense	$ 81,678	$ 87,607	$ 163,607	$ 176,256