Share Based Awards - Options activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Options Activity Rollforward
Number of Shares Available for Issuance, Beginning Balance	6,672,236	7,392,158	2,085,338
Options Outstanding, Number, Beginning Balance	11,498,747	16,435,568	13,330,882
Number of Shares Available for Issuance, Authorized	4,436,933	5,418,242	9,913,915
Number of Shares Available for Issuance, Granted	(1,316,200)	(1,089,100)	(5,373,131)
Options Outstanding, Shares Granted	1,316,200	1,089,100	5,373,131
Number of Shares Available for Issuance, other than Options granted			(16,294)
Options exercised	(1,040,902)	(2,817,915)	(1,089,708)
Exercised, withheld in net settlement		9,019
Number of Shares Available for Issuance, Canceled	1,938,053	3,208,006	1,178,737
Number of Shares Available for Issuance, Restricted stock units canceled	3,192,618	1,653,927	1,667
Number of Shares Available for Issuance, Repurchased		12,545	66,088
Number of Shares Available for Issuance, Ending Balance	4,199,415	6,672,236	7,392,158	2,085,338
Options Outstanding, Number, Ending Balance	9,835,992	11,498,747	16,435,568	13,330,882
Vested and exercisable- end of the period	7,023,833
Vested and expected to vest - end of the period	9,497,378
Options Activity, Weighted Average Exercise Price Rollforward
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 4.51	$ 4.15	$ 2.90
Options Outstanding, Weighted Average Exercise Price Granted	3.36	6.95	6.97
Options Outstanding, Weighted Average Exercise Price Exercised	2.37	2.12	2.27
Options Outstanding, Weighted Average Exercise Price Canceled	5.46	5.61	4.55
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	4.39	$ 4.51	$ 4.15	$ 2.90
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	4.08
Options Outstanding, Weighted-Average Exercise Price, Vested and expected to vest	$ 4.37
Options Outstanding, Weighted-Average Remaining Contractual Term (Years)	6 years 2 months 23 days	6 years 10 months 10 days	7 years 9 months 29 days	8 years 4 months 17 days
Options Outstanding, Aggregate Intrinsic Value	$ 5,734	$ 6,256	$ 95,791	$ 38,339
Options Outstanding, Vested and exercisable, Aggregate Intrinsic Value	5,210
Options Outstanding, Vested and expected to vest, Aggregate Intrinsic Value	$ 5,657
RSUs, excluding Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(9,070,854)	(9,932,561)	(480,456)
RSUs
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(10,724,225)	(9,932,561)	(480,456)
2016 Bonus Plans
Options Activity Rollforward
Number of Shares Available for Issuance, other than Options granted	(1,653,371)