Finance Obligation - Other information related to finance obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Sale Leaseback Transaction [Line Items]
Cash payments	$ 471	$ 255
Weighted average remaining term (years)	5 years 7 months 6 days	7 years 8 months 12 days
Weighted average discount rate (as a percent)	8.20%	8.80%
Finance obligation
Sale Leaseback Transaction [Line Items]
Cash payments	$ 44,245	$ 76,244
Weighted average remaining term (years)	5 years	5 years 3 months 18 days
Weighted average discount rate (as a percent)	11.30%	11.20%