Stock-based Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Additional disclosure
Stock-based compensation expense	$ 9,167	$ 7,396	$ 18,620	$ 11,540
Options
Number of Options
Outstanding at the beginning of period (in shares)			25,589,876
Granted (in shares)			1,538,184
Exercised (in shares)			(1,268,087)
Canceled/forfeited (in shares)			(509,987)
Outstanding at the end of the period (in shares)	25,349,986		25,349,986		25,589,876
Weighted-Average Exercise Price
Outstanding at the beginning of period (in dollars per share)			$ 9.79
Granted (in dollars per share)			16.17
Exercised (in dollars per share)			4.11
Canceled/forfeited (in dollars per share)			12.14
Outstanding at the end of the period (in dollars per share)	$ 10.41		$ 10.41		$ 9.79
Additional disclosure
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2			7 years 3 months 5 days		7 years 6 months 20 days
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2			7 years 3 months 5 days		7 years 6 months 20 days
Remaining stock-based compensation expense for unvested awards	$ 57,400		$ 57,400
Weighted average period over which remaining stock based compensation expense for unvested awards is expected to be recognized			2 years 10 months 1 day
Stock-based compensation expense	7,300	7,100	$ 14,300	11,200
Restricted stock units
Additional disclosure
Remaining stock-based compensation expense for unvested awards	14,500		$ 14,500
Weighted average period over which remaining stock based compensation expense for unvested awards is expected to be recognized			3 years 6 months 18 days
Stock-based compensation expense	$ 1,800	$ 300	$ 4,300	$ 300