Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Facility operating expense	$ 4,604		$ 9,229
Facility lease expense	67,689	$ 81,960	136,357	$ 162,360
Operating lease expense	72,293		145,586
Operating lease expense adjustment	4,429		8,812
Operating cash flows from operating leases	76,722		154,398
Non-cash recognition of right-of-use assets obtained in exchange for new operating lease obligations	2,623		3,981
Depreciation and amortization	11,677		23,355
Interest expense: financing lease obligations	16,649	$ 22,389	33,392	$ 45,320
Financing lease expense	28,326		56,747
Operating cash flows from financing leases	16,649		33,392
Financing cash flows from financing leases	5,500		10,953
Total cash flows from financing leases	$ 22,149		$ 44,345