Operating Expenses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Expenses [Abstract]
Salaries and wages									$ 68,668	$ 61,301	$ 56,750
Employee benefits									15,715	13,192	11,666
Equipment and software									13,112	11,935	13,446
Occupancy									12,413	12,974	11,491
Outside processing/service fees									7,867	7,093	5,497
Professional fees									4,347	4,128	5,589
FDIC insurance premiums									4,320	5,375	7,388
Credit-related expenses									3,816	9,535	8,197
Postage and courier									3,149	3,147	3,115
Advertising and marketing									3,106	2,850	3,054
Training, travel and other employee expenses									2,530	2,246	1,765
Donations									1,892	1,537	991
Telephone									1,693	1,631	1,768
Intangible asset amortization									1,569	1,860	1,705
Supplies									1,567	1,690	1,740
Other									3,345	1,509	2,640
Total Operating Expenses	$ 41,211	$ 36,066	$ 35,537	$ 36,295	$ 37,807	$ 35,394	$ 33,413	$ 35,389	$ 149,109	$ 142,003	$ 136,802