Organization, Basis of Presentation and Summary of Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator:
Net income (loss) available to common stockholders	$ (4,143)	$ (4,813)	$ (6,825)	$ (9,682)	$ (9,525)	$ (134,481)	$ (7,847)	$ (7,753)	$ (25,463)	$ (159,606)	$ 12,346
Denominator:
Weighted average shares outstanding - basic	35,882	35,879	36,045	35,590	35,696	35,728	35,775	35,263	35,849	35,617	34,204
Potential common shares - options (treasury stock method)											411
Weighted average shares outstanding - diluted	35,882	35,879	36,045	35,590	35,696	35,728	35,775	35,263	35,849	35,617	34,615
Shares excluded (anti-dilutive)									174	126
Shares excluded due to an exercise price greater than weighted average stock price for the period									1,453	1,561	1,950
Net income (loss) per common share:
Basic	$ (0.12)	$ (0.13)	$ (0.19)	$ (0.27)	$ (0.27)	$ (3.76)	$ (0.22)	$ (0.22)	$ (0.71)	$ (4.48)	$ 0.36
Diluted	$ (0.12)	$ (0.13)	$ (0.19)	$ (0.27)	$ (0.27)	$ (3.76)	$ (0.22)	$ (0.22)	$ (0.71)	$ (4.48)	$ 0.36