Revenues - Narrative, Remaining Performance Obligation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Operating Lease, Lease Income	$ 86,300		$ 179,500
Contract with Customer, Liability, Revenue Recognized	5,100		12,600
Revenue, Remaining Performance Obligation, Amount	2,269,000		2,269,000
Contract With Customer, Liability, Revenue Recognized, Billed Prior Period			700	$ 600
Contract With Customer, Asset, Revenue Recognized	200		400
Revenue from Contract with Customer, Excluding Assessed Tax	114,807	$ 130,751	242,661	$ 265,248
Shortfall Payments
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Liability	500		500
Service, Other
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 28,500		$ 63,200