Selected Quarterly Financial Data (Unaudited) Selected Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, 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
Interest income	$ 9,943	$ 10,248	$ 10,532	$ 10,609	$ 10,734	$ 10,745	$ 11,216	$ 11,009	$ 41,332	$ 43,704	$ 46,770
Interest expense	1,301	1,399	1,588	1,686	1,768	1,896	2,033	2,156	5,974	7,853	10,187
Net interest income	8,642	8,849	8,944	8,923	8,966	8,849	9,183	8,853	35,358	35,851	36,583
Provision for loan losses	850	1,160	1,150	1,050	12,542	2,673	996	903	4,210	17,114	3,877
Net interest income after provision for loan losses	7,792	7,689	7,794	7,873	(3,576)	6,176	8,187	7,950	31,148	18,737	32,706
Non-interest income	3,510	3,032	2,643	2,824	2,534	3,320	4,542	2,455	12,009	12,851	9,236
Non-interest expense	9,082	8,969	8,542	10,207	10,893	9,186	11,071	9,967	36,800	41,117	37,775
Income (loss) before income tax expense (benefit)	2,220	1,752	1,895	490	(11,935)	310	1,658	438	6,357	(9,529)	4,167
Income tax expense	658	493	541	0	638	(84)	425	(34)	1,692	945	707
Net income (loss)	$ 1,562	$ 1,259	$ 1,354	$ 490	$ (12,573)	$ 394	$ 1,233	$ 472	$ 4,665	$ (10,474)	$ 3,460
Basic earnings (loss) per share	$ 0.15	$ 0.12	$ 0.13	$ 0.05	$ (1.17)	$ 0.04	$ 0.12	$ 0.04	$ 0.43	$ (0.98)	$ 0.33
Diluted earnings (loss) per share	$ 0.14	$ 0.12	$ 0.13	$ 0.05	$ (1.17)	$ 0.04	$ 0.11	$ 0.04	$ 0.43	$ (0.98)	$ 0.32
Dividends declared per common share	$ 0.01	$ 0.02	$ 0	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.04	$ 0.04	$ 0.04