Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Leases [Abstract]
Operating lease right-of-use assets	$ 43,374	$ 45,792	$ 36,930
Operating - current	9,777	9,143	8,099
Operating - noncurrent	34,087	37,199	28,893
Total operating lease liabilities	43,864	46,342	36,992
Property and equipment, gross	3,569	3,569	3,569
Accumulated amortization	(3,264)	(3,112)	(2,953)
Property and equipment, net	305	457	616
Other current liabilities	48	384	998
Total finance lease liabilities	$ 48	$ 384	$ 998