Stock-Based Compensation - Outstanding Stock-based Compensation Awards (Details) - USD ($)					12 Months Ended
	Dec. 11, 2020	Oct. 15, 2020	Dec. 03, 2019	Nov. 18, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Stock Option Awards
Beginning Balance (in shares)					5,875,829	6,069,907
Granted (in shares)	482,000	388,292	5,556	2,549,556	872,003	2,555,109	0
Exercises (net cash settled, see Tender Offer below)					(130,017)	(2,326,019)
Exercises (issuance of shares)					(2,143,317)	(111,660)
Forfeitures/expirations (in shares)					(196,338)	(311,508)
Ending Balance (in shares)					4,278,160	5,875,829	6,069,907
Options exercisable (in shares)					992,061	2,341,193
Weighted- Average Exercise Price
Beginning Balance (in dollars per share)					$ 9.29	$ 3.87
Granted (in dollars per share)	$ 10.35	$ 13.82	$ 16.20	$ 16.20	11.90	16.20
Exercises (net cash settled, see Tender Offer below) (in dollars per share)					3.68	3.69
Exercises (issuance of shares)					3.69	3.92
Forfeitures/expirations (in dollars per share)					13.22	4.18
Ending Balance (in dollars per share)					11.20	9.29	$ 3.87
Options exercisable (in dollars per share)					$ 4.28	$ 3.80
Weighted- Average Remaining Contractual Term (years)
Outstanding					8 years 4 months 9 days	8 years 1 month 24 days	6 years 9 months 14 days
Granted					9 years 10 months 13 days	9 years 10 months 17 days
Exercises (net cash settled, see Tender Offer below)					5 years 8 months 26 days	6 years 9 months
Exercises (issuance of shares)					5 years 9 months 7 days	6 years 9 months 10 days
Forfeitures/expirations					8 years 7 months 20 days	6 years 9 months 21 days
Options exercisable					5 years 9 months 21 days	6 years 9 months 10 days
Aggregate Intrinsic Value
Outstanding stock option awards at January 1					$ 42,433,615	$ 90,463,239
Granted					1,393,499	0
Exercises (net cash settled, see Tender Offer below)					896,335	33,901,447
Exercises (issuance of shares)					15,510,765	1,420,239
Forfeitures/expirations					(146,415)	3,745,889
Outstanding stock option awards as of December 31, 2020					9,855,005	42,433,615	$ 90,463,239
Options exercisable as of December 31					$ 9,151,100	$ 29,029,972