Share Based Awards - Options activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Options Activity Rollforward
Number of Shares Available for Issuance, Beginning Balance	4,199,415
Options Outstanding, Number, Beginning Balance	9,835,992
Number of Shares Available for Issuance, Authorized	4,453,425
Number of Shares Available for Issuance, Granted	(100,000)
Options Outstanding, Shares Granted	100,000
Options exercised	(392,606)
Number of Shares Available for Issuance, Canceled	765,252
Number of Shares Available for Issuance, Ending Balance	6,306,437	4,199,415
Options Outstanding, Number, Ending Balance	8,778,134	9,835,992
Vested and exercisable- end of the period	6,846,658
Vested and expected to vest - end of the period	8,538,551
Options Activity, Weighted Average Exercise Price Rollforward
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 4.39
Options Outstanding, Weighted Average Exercise Price Granted	4.90
Options Outstanding, Weighted Average Exercise Price Exercised	2.58
Options Outstanding, Weighted Average Exercise Price Canceled	6.14
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	4.33	$ 4.39
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	4.13
Options Outstanding, Weighted-Average Exercise Price, Vested and expected to vest	$ 4.32
Options Outstanding, Weighted-Average Remaining Contractual Term (Years)	5 years 3 months 29 days	6 years 2 months 23 days
Options Outstanding, Aggregate Intrinsic Value	$ 7,974	$ 5,734
Options Outstanding, Vested and exercisable, Aggregate Intrinsic Value	7,090
Options Outstanding, Vested and expected to vest, Aggregate Intrinsic Value	$ 7,836
RSUs, excluding Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(2,709,052)
RSUs
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(4,397,129)
Share withheld from net settlement of restricted stock units	(677,547)
Number of Shares Available for Issuance, Restricted stock units canceled	707,927
2016 Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(1,688,077)
Share withheld from net settlement of restricted stock units	(677,547)