Commitments and Contingencies - Finance Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Total Payments of future minimum lease payments
Remainder of 2020	$ 31,325		$ 31,325
2021	61,684		61,684
2022	56,815		56,815
2023	49,159		49,159
2024	62,196		62,196
2025 and thereafter	53,518		53,518
Total future minimum lease payments	314,697		314,697
Less imputed lease interest	(85,558)		(85,558)
Sale of future services	129,209		129,209
Total lease liabilities	358,348		358,348
Total future minimum lease payments	155,910		155,910
Finance lease costs
Amortization of right of use asset			1,740	$ 1,558
Interest on finance obligations			1,223	2,656
Total finance lease cost			2,963	4,214
Right of use assets obtained in exchange for new finance lease liabilities	$ 0	$ 700	0	700
Other information
Cash payments			$ 5,196	$ 55,913
Weighted average remaining lease term (years)	3 years 6 months 10 days	3 years 3 months	3 years 6 months 10 days	3 years 3 months
Weighted average discount rate	8.00%	10.80%	8.00%	10.80%
Restricted Cash
Restricted cash	$ 131,100		$ 131,100
Letter of credit	98,200		98,200
Aggregate amount of financial obligation	141,200		141,200
Letter of Credit
Restricted Cash
Aggregate amount of financial obligation	500		500
Sale Leaseback Agreements
Total Payments of future minimum lease payments
Total lease liabilities	27,900		27,900		$ 31,700
Finance Lease [Member]
Total Payments of future minimum lease payments
Remainder of 2020	5,066		5,066
2021	9,276		9,276
2022	4,975		4,975
2023	3,149		3,149
2024	16,154		16,154
Total future minimum lease payments	38,620		38,620
Less imputed lease interest	(10,718)		(10,718)
Total lease liabilities	27,902		27,902
Other Leased Property [Member]
Total Payments of future minimum lease payments
Remainder of 2020	312		312
2021	590		590
2022	573		573
2023	549		549
2024	632		632
2025 and thereafter	1,174		1,174
Total future minimum lease payments	3,830		3,830
Less imputed lease interest	(1,020)		(1,020)
Total lease liabilities	2,810		2,810
Finance obligation | Property and equipment
Total Payments of future minimum lease payments
Total future minimum lease payments	$ 2,800		$ 2,800		$ 2,800