Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
Contractual interest expense	$ 1,801	$ 1,511	$ 3,582	$ 2,964
Accretion of debt discount	212	173	411	373
Total interest expense	$ 2,013	$ 1,684	$ 3,993	$ 3,337