Description of Business and Basis of Presentation (Details 1) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Outstanding options to purchase common stock
Schedule of instruments convertible into common shares that are not included in the denominator used in the diluted net income (loss) per share calculation because to do so would be anti-dilutive
Anti-dilutive, shares	544	178
Restricted stock awards
Schedule of instruments convertible into common shares that are not included in the denominator used in the diluted net income (loss) per share calculation because to do so would be anti-dilutive
Anti-dilutive, shares	442	230
Restricted stock unit awards
Schedule of instruments convertible into common shares that are not included in the denominator used in the diluted net income (loss) per share calculation because to do so would be anti-dilutive
Anti-dilutive, shares	57	0
Employee stock purchase plan
Schedule of instruments convertible into common shares that are not included in the denominator used in the diluted net income (loss) per share calculation because to do so would be anti-dilutive
Anti-dilutive, shares	0	0