Employee Benefit Plans - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Number of Shares
Outstanding, vested and expected to vest, Beginning balance | shares	15,812,928
Granted | shares	2,312,230
Exercised | shares	(1,920,482)
Forfeited | shares	(112,088)
Expired | shares	(23,376)
Outstanding, vested and expected to vest, Ending balance | shares	16,069,212	15,812,928
Vested and exercisable at June 30, 2020 | shares	9,760,821
Weighted Average Exercise Price
Outstanding, vested and expected to vest, Beginning balance | $ / shares	$ 14.67
Granted | $ / shares	21.15
Exercised | $ / shares	13.34
Forfeited | $ / shares	13.43
Expired | $ / shares	14.73
Outstanding, vested and expected to vest, Ending balance | $ / shares	15.77	$ 14.67
Vested and exercisable at June 30, 2020 | $ / shares	$ 15.15
Additional Disclosures
Outstanding, vested and expected to vest, Aggregate Intrinsic Value, Beginning balance | $	$ 124,927	$ 50,994
Vested and exercisable at June 30, 2020 | $	$ 81,850
Outstanding, vested and expected to vest, Weighted Average Remaining Contractual Term	7 years 4 months 24 days	7 years 4 months 24 days
Vested and exercisable, Weighted Average Remaining Contractual Term	6 years 4 months 24 days