Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Numerator:
Net loss available to common stockholders	$ (6,158)	$ (9,682)
Denominator:
Weighted average shares outstanding - basic	36,614	35,590
Potential common shares - options (treasury stock method)
Weighted average shares outstanding - diluted	36,614	35,590
Shares excluded (anti-dilutive)	70	40
Shares excluded due to an exercise price greater than weighted average stock price for the period	1,473	1,567
Net loss per common share:
Basic	$ (0.17)	$ (0.27)
Diluted	$ (0.17)	$ (0.27)