Stock-Based Compensation - Schedule of Share-based Compensation, Additional Information (Details) (Stock Options and Restricted Stock Units [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock Options and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of options outstanding (in usd per share)	$ 1.35	$ 2.88	$ 11.52
Aggregate intrinsic value of options exercised	$ 9,000	$ 226,000	$ 61,000
Total fair value of shares vested	$ 3,564,000	$ 2,340,000	$ 660,000