Stock-Based Compensation - Stock options (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended		12 Months Ended	38 Months Ended
	May 03, 2019	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Jun. 30, 2022
2015 Plan
Number of Shares
Outstanding at the beginning (in shares)		4,545,794
Granted (in shares)		1,704,850
Exercised (in shares)		(50,420)
Forfeitures (in shares)		(818,944)
Outstanding at the end (in shares)		5,381,280		4,545,794	5,381,280
Exercisable at the end (in shares)		2,444,111			2,444,111
Weighted Average Exercise Price
Outstanding at the beginning (in dollars per share)		$ 14.15
Granted (in dollars per share)		5.39
Exercised (in dollars per share)		1.32
Forfeited (in dollars per share)		13.76
Outstanding at the end (in dollars per share)		11.56		$ 14.15	$ 11.56
Exercisable at the end (in dollars per share)		$ 12.84			$ 12.84
Weighted Average Remaining Contractual Life (Years) And Aggregate Intrinsic Value
Outstanding (in years)		8 years 1 month 6 days		8 years 1 month 6 days
Exercisable at the end (in years)		7 years
Outstanding at the beginning (in dollars)		$ 2,860
Outstanding at the end (in dollars)		1,935		$ 2,860	$ 1,935
Exercisable at the end (in dollars)		$ 1,870			1,870
Weighted average grant date fair value per share of stock options granted		$ 3.72
Aggregate intrinsic value of stock options exercised		$ 200
Aggregate grant date fair value		6,900	$ 10,300
Share Based Compensation Expense Not Recognized
Unrecognized compensation cost		$ 19,700			$ 19,700
Compensation expense recognition period		2 years 10 months 24 days
Omnibus Incentive Plan
Stock Based Compensation
Total number of shares of common stock that may be issued		2,900,000			2,900,000
Annual increase in number of share reserved for issuance (as percent)	4.00%
2015 Plan and 2019 Employee Stock Purchase Plan
Stock Based Compensation
Vesting period		4 years
Expiration period		10 years
Number of shares reserved for issuance under the plan		2,534,766			2,534,766
2019 Employee Stock Purchase Plan
Stock Based Compensation
Number of shares issued					23,891
Number of shares reserved for issuance under the plan		766,789			766,789