Net Income (Loss) Per Share (Details 1)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Antidilutive effect of diluted net income (loss) per share
Stock units	1,943	3,631,949	972	3,624,257
Stock options	2,338,277	2,866,073	2,079,437	2,714,847
Shares issuable upon conversion of convertible debt	13,507,407	14,855,755	13,498,059	14,934,459
Unvested restricted stock	297,850	759,524	274,604	919,785