Stock-Based Compensation - Stock Option Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Number of Shares
Beginning stock options outstanding (in shares)	2,128,906	1,308,998	1,186,320
Granted (in shares)	262,051	953,800	217,552
Exercised (in shares)	(56,658)	(32,124)	(82,510)
Forfeited (in shares)	(50,457)	(101,768)	(12,364)
Ending stock options outstanding (in shares)	2,283,842	2,128,906	1,308,998
Weighted Average Exercise Price Per Share
Beginning stock options outstanding (in dollars per share)	$ 9.42	$ 12.30	$ 11.76
Granted (in dollars per share)	$ 6.56	$ 6.02	$ 13.78
Exercised (in dollars per share)	$ 5.27	$ 5.78	$ 8.11
Forfeited (in dollars per share)	$ 7.97	$ 15.68	$ 14.97
Ending stock options outstanding (in dollars per share)	$ 9.23	$ 9.42	$ 12.30
Vested at December 31, 2012 and expected to vest
Number of Shares	2,231,215
Weighted Average Exercise Price Per Share (in dollars per share)	$ 9.30
Weighted Average Contractual Life	8 years 0 months 15 days
Aggregate Intrinsic Value	$ 947
Exercisable at December 31, 2012
Number of Shares	1,303,709
Weighted Average Exercise Price Per Share (in dollars per share)	$ 11.20
Weighted Average Contractual Life	6 years 6 months 7 days
Aggregate Intrinsic Value	$ 373