Income Taxes (Effective Tax Rate) (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
Amount
Income tax computed at statutory federal tax rate									$ 10,469	$ 5,890	$ 1,956
Tax-exempt interest income									(565)	(574)	(808)
Investments in tax credit funds									(387)	(497)	(715)
Bank owned life insurance									(14)	(44)	(207)
Other, net									22	(179)	(54)
Total income tax expense	$ 1,665	$ 2,310	$ 2,471	$ 3,079	$ 1,333	$ 1,885	$ 887	$ 491	$ 9,525	$ 4,596	$ 172
Rate
Income tax computed at statutory federal tax rate									35.00%	34.30%	34.00%
Tax-exempt interest income									(1.90%)	(3.40%)	(14.10%)
Investments in tax credit funds									(1.30%)	(2.90%)	(12.40%)
Bank owned life insurance									(0.10%)	(0.30%)	(3.60%)
Other, net									0.10%	(0.90%)	(0.90%)
Total income tax expense									31.80%	26.80%	3.00%