Net Income Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,149,044	1,833,574	2,005,642
Earnings Per Share, Basic [Abstract]
Net income	$ 16,178	$ 10,389	$ 4,892
Weighted Average Number of Shares Outstanding, Basic	33,307,000	33,123,000	32,651,000
Net income per share-basic	$ 0.49	$ 0.31	$ 0.15
Earnings Per Share, Diluted [Abstract]
Net income	$ 16,178	$ 10,389	$ 4,892
Weighted Average Number of Shares Outstanding, Basic	33,307,000	33,123,000	32,651,000
Incremental Common Shares Attributable to Share-based Payment Arrangements	906,000	980,000	862,000
Weighted Average Number of Shares Outstanding, Diluted	34,213,000	34,103,000	33,513,000
Net income per share - diluted	$ 0.47	$ 0.30	$ 0.15