Stock-based Compensation - Stock Option Plan Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Outstanding Shares
Beginning balance (in shares)	2,866,675
Granted (in shares)	82,300
Exercised (in shares)	(144,989)
Canceled (in shares)	(19,235)
Ending balance (in shares)	2,784,751
Vested and expected to vest (in shares)	2,620,436
Exercisable (in shares)	2,073,385
Weighted Average Exercise Price
Weighted average exercise price, Beginning balance (in dollars per share)	$ 40.54
Weighted average exercise price, granted (in dollars per share)	88.57
Weighted average exercise price, exercised (in dollars per share)	32.51
Weighted average exercise price, canceled (in dollars per share)	80.57
Weighted average exercise price, Ending balance (in dollars per share)	42.11
Weighted average exercise price, Vested and expected to vest (in dollars per share)	39.53
Weighted average exercise price, Exercisable (in dollars per share)	$ 29.22
Weighted Average Remaining Contractual Life
Weighted average remaining contractual life (in years)	6 years 2 months 12 days	6 years
Weighted Average Remaining Contractual Life (Years), Vested and Expected to Vest	6 years
Weighted Average Remaining Contractual Life (Years), Exercisable	5 years 3 months 18 days
Aggregate Intrinsic Value
Aggregate intrinsic value	$ 126,495		$ 125,647
Aggregate intrinsic value, Vested and expected to vest	125,595
Aggregate intrinsic value, Exercisable	$ 120,221