Income (Loss) per Share (Calculation of Basic and Diluted Net Income (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Basic and dilutive numerator:
Net income (loss)	$ 893	$ 2,489
Denominator:
Weighted-average shares outstanding—basic	46,069	45,041
Net effect of dilutive securities:
Incremental shares from equity awards	1,988	1,769
Weighted-average shares outstanding — diluted	48,057	46,810
Net income (loss) per share — basic	$ 0.02	$ 0.06
Net income (loss) per share — diluted	$ 0.02	$ 0.05