Income (Loss) per Share (Calculation of Basic and Diluted Net Loss Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Basic and dilutive numerator:
Net income (loss)	$ 6,895	$ (6,647)	$ 9,384	$ (7,312)
Denominator:
Shares outstanding	44,957	44,849	44,999	44,725
Weighted-average shares outstanding—basic	44,957	44,849	44,999	44,725
Net effect of dilutive securities:
Incremental shares from equity awards	1,011		713
Weighted-average shares outstanding—diluted	45,968	44,849	45,712	44,725
Net income (loss) per share — basic	$ 0.15	$ (0.15)	$ 0.21	$ (0.16)
Net income (loss) per share — diluted	$ 0.15	$ (0.15)	$ 0.21	$ (0.16)