Leases Lessor (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Lessor Disclosure [Abstract]
Operating Lease, Right-of-Use Asset	$ 253,000,000	$ 253,000,000
Operating Lease, Lease Income	155,000,000	308,000,000
Variable Lease, Income	24,000,000	36,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract]
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter	40,000,000	40,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received	49,000,000	49,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years	2,000,000	2,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years	2,000,000	2,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years	2,000,000	2,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years	2,000,000	2,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Next Twelve Months	1,000,000	1,000,000
Sales-type and Direct Financing Leases, Lease Receivables, Gross Difference, Amount [Abstract]
Sales-type and Direct Financing Leases, Lease Receivable	22,000,000	22,000,000
Sales-type and Direct Financing Leases, Lease Receivable, Undiscounted Excess Amount	(27,000,000)	(27,000,000)
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
Lessor, Operating Lease, Payments to be Received, Next Twelve Months	256,000,000	256,000,000
Lessor, Operating Lease, Payments to be Received, Two Years	502,000,000	502,000,000
Lessor, Operating Lease, Payments to be Received, Three Years	474,000,000	474,000,000
Lessor, Operating Lease, Payments to be Received, Four Years	459,000,000	459,000,000
Lessor, Operating Lease, Payments to be Received, Five Years	395,000,000	395,000,000
Lessor, Operating Lease, Payments to be Received, Thereafter	1,823,000,000	1,823,000,000
Lessor, Operating Lease, Payments to be Received	3,909,000,000	3,909,000,000
Operating Lease, Risk Strategy, Residual Asset	8,440,000,000	8,440,000,000	$ 8,227,000,000
Property Subject to Operating Lease [Member]
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
Operating Lease, Risk Strategy, Residual Asset	1,100,000,000	1,100,000,000
Property, Plant and Equipment, Gross	$ 3,200,000,000	$ 3,200,000,000