Revenues - Narrative, Remaining Performance Obligation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Operating Lease, Lease Income	$ 90,100		$ 269,900
Contract with Customer, Liability, Revenue Recognized	1,100		13,800
Revenue, Remaining Performance Obligation, Amount	2,174,000		2,174,000
Contract With Customer, Liability, Revenue Recognized, Billed Prior Period	200		700	$ 600
Contract With Customer, Asset, Revenue Recognized	100		500
Revenue from Contract with Customer, Excluding Assessed Tax	127,731	$ 135,895	370,392	$ 401,143
Shortfall Payments
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Liability	400		400
Service, Other
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 37,700		$ 100,500