Net Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net Earnings per Share
Net earnings	$ 2,930	$ 3,219	$ 4,038	$ 5,380
Basic:
Weighted average common shares outstanding	18,919,000	18,064,000	18,919,000	18,064,000
Weighted average common shares of restricted stock that has not vested	(1,319,000)	(1,011,000)	(1,353,000)	(1,052,000)
Shares used in the computation of basic net earnings per share	17,600,000	17,053,000	17,566,000	17,012,000
Net earnings per share - basic (in dollars per share)	$ 0.17	$ 0.19	$ 0.23	$ 0.32
Diluted:
Shares used in the computation of basic net earnings per share	17,600,000	17,053,000	17,566,000	17,012,000
Employee and non-employee director stock options (in shares)	48,000	113,000	40,000	105,000
Restricted stock that has not yet vested (in shares)	455,000	279,000	380,000	266,000
Shares used in the computation of diluted net earnings per share	18,103,000	17,445,000	17,986,000	17,383,000
Net earnings per share - diluted (in dollars per share)	$ 0.16	$ 0.18	$ 0.22	$ 0.31
Restricted common stock that has not yet vested
Anti-dilutive shares
Restricted common stock that has not yet vested	83,000	27,000	326,500	27,000