Stock Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 16, 2019	Jul. 23, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Number of Stock Options
Beginning balance (in shares)			3,771,690	3,774,337	3,784,044	3,784,044	0	0
Forfeited (in shares)			(44,485)	(2,647)	(9,707)
Granted (in shares)	184,378	3,589,959					3,707,901
Ending balance (in shares)			3,727,205	3,771,690	3,774,337	3,727,205	3,707,901	3,784,044
Options exercisable (in shares)			727,438			727,438	0
Weighted Average Exercise Price
Beginning balance (in dollars per share)			$ 15.67	$ 15.67	$ 15.67	$ 15.67	$ 0	$ 0
Forfeited (in dollars per share)			15.95	15.60	15.60
Granted (in dollars per share)	$ 17.00	$ 15.60					15.60
Ending balance (in dollars per share)			15.67	$ 15.67	$ 15.67	15.67	15.60	$ 15.67
Options exercisable (in dollars per share)			$ 15.62			$ 15.62	$ 0
Weighted Average Remaining Contractual Term (in years)
Options outstanding			8 years 9 months 18 days	9 years 1 month 6 days	9 years 3 months 18 days		9 years 9 months 18 days	9 years 7 months 6 days
Options granted							9 years 9 months 18 days
Options exercisable						8 years 8 months 12 days
Aggregate Intrinsic Value
Options outstanding			$ 0	$ 0	$ 0	$ 0	$ 704,501	$ 4,812,490	$ 0
Options granted							$ 704,501