Share Based Awards - Options activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Options Activity Rollforward
Number of Shares Available for Issuance, Beginning Balance	4,199,415	4,199,415
Options Outstanding, Number, Beginning Balance	9,835,992	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		(1,033,121)
Number of Shares Available for Issuance, Cancelled		1,006,137
Number of Shares Available for Issuance, Ending Balance		2,521,805	4,199,415
Options Outstanding, Number, Ending Balance		7,896,734	9,835,992
Vested and exercisable- end of the period		6,593,808
Vested and expected to vest - end of the period		7,752,157
Options Activity, Weighted Average Exercise Price Rollforward
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 4.39	$ 4.39
Options Outstanding, Weighted Average Exercise Price Granted		4.90
Options Outstanding, Weighted Average Exercise Price Exercised		2.99
Options Outstanding, Weighted Average Exercise Price Cancelled		6.31
Options Outstanding, Weighted-Average Exercise Price, Ending Balance		4.34	$ 4.39
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable		4.26
Options Outstanding, Weighted-Average Exercise Price, Vested and expected to vest		$ 4.34
Options Outstanding, Weighted-Average Remaining Contractual Term (Years)		4 years 10 months 2 days	6 years 2 months 23 days
Options Outstanding, Aggregate Intrinsic Value		$ 4,387	$ 5,734
Options Outstanding, Vested and exercisable, Aggregate Intrinsic Value		4,147
Options Outstanding, Vested and expected to vest, Aggregate Intrinsic Value		$ 4,354
RSUs, excluding Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted		(7,981,401)
Unvested restricted stock units
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted		(9,669,478)
Number of Shares Available for Issuance, Restricted stock units cancelled		1,954,759
Common Stock
Options Activity Rollforward
Share withheld from net settlement of restricted stock units	(677,547)	(677,547)
2016 Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted		(1,688,077)