Stock-Based Compensation - Summary of Stock Option and Related Information (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Subject to Outstanding Options, Beginning Balance | shares	3,701,461
Shares Subject to Outstanding Options, granted | shares	1,371,130
Shares Subject to Outstanding Options, exercised | shares	(337,846)
Shares Subject to Outstanding Options, canceled | shares	(160,587)
Shares Subject to Outstanding Options, Ending Balance | shares	4,574,158
Shares Subject to Outstanding Options, Exercisable | shares	2,380,560
Shares Subject to Outstanding Options, Vested and expected to vest | shares	4,574,158
Weighted Average Exercise Price per Share, Beginning Balance | $ / shares	$ 26.40
Weighted Average Exercise Price Per Share, granted | $ / shares	43.27
Weighted Average Exercise Price per Share, exercised | $ / shares	15.78
Weighted Average Exercise Price Per Share, cancelled | $ / shares	38.75
Weighted Average Exercise Price per Share, Ending Balance | $ / shares	31.81
Weighted Average Exercise Price Per Share, Exercisable | $ / shares	23.21
Weighted Average Exercise Price Per Share, Vested and expected to vest | $ / shares	$ 31.81
Weighted Average Remaining Contractual Term	7 years 8 months 12 days
Weighted Average Remaining Contractual Term, Exercisable	7 years
Weighted Average Remaining Contractual Term, Vested and expected to vest	7 years 8 months 12 days
Aggregate Intrinsic Value, Beginning Balance | $	$ 187,879
Aggregate Intrinsic Value, Exercisable | $	118,246
Aggregate Intrinsic Value, Vested and expected to vest | $	$ 187,879