Earnings (Loss) Per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator:
Net income (loss)	$ (239)	$ 4,877	$ (5,381)	$ 6,211
Denominator:
Weighted-average common shares outstanding (shares)	27,744	29,396	29,203	29,075
Basic earnings (loss) per common share (in dollars per share)	$ (0.01)	$ 0.17	$ (0.18)	$ 0.21
Numerator:
Net income (loss)	$ (239)	$ 4,877	$ (5,381)	$ 6,211
Denominator:
Weighted-average common shares outstanding (shares)	27,744	29,396	29,203	29,075
Incremental shares from stock-based compensation plans (shares)	0	419	0	442
Denominator for diluted earnings (loss) per common share (shares)	27,744	29,815	29,203	29,517
Diluted earnings (loss) per common share (in dollars per share)	$ (0.01)	$ 0.16	$ (0.18)	$ 0.21