Equity Incentive Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Shares
Options outstanding beginning balance	5,884,742
Options granted	211,243
Options exercised	(532,848)
Options cancelled or expired	(79,246)
Options outstanding ending balance	5,483,891	5,884,742
Options exercisable	2,997,298
Weighted Average Exercise Price
Options outstanding beginning balance	$ 20.09
Options granted	68.61
Options exercised	14.88
Options cancelled or expired	15.77
Options outstanding ending balance	22.53	$ 20.09
Options exercisable	$ 15.35
Weighted Average Remaining Contractual Life (Years)
Options outstanding	7 years 1 month 9 days	7 years 2 months 19 days
Options exercisable	6 years 2 months 15 days
Aggregate Intrinsic Value
Options outstanding	$ 285,564	$ 312,838
Options exercisable	$ 177,582