Summary of Significant Accounting Policies (Details 3) (USD $)	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
Net earnings per common share - basic:
Net earnings	$ (528,000)	$ 1,147,000	$ 1,817,000	$ 2,371,000	$ 2,120,000	$ 2,039,000	$ 1,238,000	$ (38,000)	$ 4,807,000	$ 5,359,000	$ 6,743,000
Net earnings allocated to nonvested restricted stock awards									111,000	124,000	144,000
Net earnings available to common stockholders									4,696,000	5,235,000	6,599,000
Weighted-average shares outstanding									31,745,000	31,645,000	31,555,000
Net earnings per common share - basic (in dollars per share)	$ (0.02)	$ 0.04	$ 0.06	$ 0.07	$ 0.07	$ 0.06	$ 0.04		$ 0.15	$ 0.17	$ 0.21
Net earnings per common share - diluted:
Net earnings	(528,000)	1,147,000	1,817,000	2,371,000	2,120,000	2,039,000	1,238,000	(38,000)	4,807,000	5,359,000	6,743,000
Net earnings allocated to nonvested restricted stock awards									111,000	124,000	144,000
Net earnings available to common stockholders									4,696,000	5,235,000	6,599,000
Weighted-average shares outstanding									31,745,000	31,645,000	31,555,000
Weighted-average shares and dilutive shares outstanding									31,745,000	31,645,000	31,555,000
Net earnings per common share - diluted (in dollars per share)	$ (0.02)	$ 0.04	$ 0.06	$ 0.07	$ 0.07	$ 0.06	$ 0.04		$ 0.15	$ 0.17	$ 0.21
Anti-dilutive securities not included in the computation of diluted EPS (in shares)										9,000	438,000
Accounting for stock-based compensation
Stock-based compensation expense for restricted stock awards and stock options									793,000	905,000	1,192,000
Income tax benefit related to restricted stock awards									$ 59,000	$ 142,000	$ 248,000