Stockholders' Equity and Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Number of shares
Outstanding, beginning of period (in shares)	5,171
Options exercised (in shares)	(867)
Options canceled (in shares)	(65)
Outstanding, end of period (in shares)	4,239	5,171
Weighted average exercise price
Outstanding, beginning of period (in dollars per share)	$ 1.60
Options exercised (in dollars per share)	1.80
Options canceled (in dollars per share)	2.52
Outstanding, end of period (in dollars per share)	$ 1.54	$ 1.60
Outstanding, Weighted average remaining contractual term (years)	6 years 1 month 22 days	7 years 2 months 12 days
Outstanding, Aggregate intrinsic value	$ 79,443	$ 83,700
Options exercisable at end of period
Options exercisable (in shares)	3,047
Weighted average exercise price (in dollars per share)	$ 1.03
Weighted average remaining contractual term (years)	5 years 8 months 2 days
Aggregate intrinsic value	$ 58,654
Options vested as of end of period and expected to vest after end of period
Options vested and expected to vest (in shares)	4,239
Weighted average exercise price (in dollars per share)	$ 1.54
Weighted average remaining contractual term (years)	6 years 1 month 22 days
Aggregate intrinsic value	$ 79,443