Basic and Diluted Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands		3 Months Ended		12 Months Ended
	Aug. 17, 2015	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Feb. 14, 2014
Components of basic and diluted net income (loss) per share
Net loss		$ (36,560,000)	$ (7,527,000)
Weighted average shares outstanding used to compute net loss per share:
Basic (in shares)		34,378	34,739
Diluted (in shares)		34,378	34,739
Net income (loss) per share:
Basic (in usd per share)		$ (1.06)	$ (0.22)
Diluted (in usd per share)		$ (1.06)	$ (0.22)
Anti-dilutive securities (in shares)		17,945	18,123
Options to purchase shares of common stock
Net income (loss) per share:
Anti-dilutive securities (in shares)		2,406	2,455
Shares of common stock issuable upon the vesting of RSUs
Net income (loss) per share:
Anti-dilutive securities (in shares)		775	904
Warrants
Net income (loss) per share:
Anti-dilutive securities (in shares)		7,382	7,382
Convertible 2.5% notes
Net income (loss) per share:
Anti-dilutive securities (in shares)		7,382	7,382
Convertible 2.5% notes, net
Basic and Diluted Net Income (Loss) per Share
Principal amount of debt at time of issuance		$ 200,000,000.0				$ 200,000,000
Interest rate (as a percent)		2.50%			2.50%
2015 Term Loan Facility
Basic and Diluted Net Income (Loss) per Share
Principal amount of debt at time of issuance	$ 350,000,000			$ 350,000,000.0
Debt term (in years)	6 years			6 years