Leases Lessor (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lessor Disclosure [Abstract]
Operating Lease, Lease Income	$ 153	$ 155	$ 288	$ 308
Variable Lease, Income	23	24	34	36
Lease Income	130	$ 131	254	$ 272
Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract]
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, after Year Five	38		38
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received	47		47
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Five	2		2
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Four	2		2
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Three	2		2
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Two	2		2
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year One	1		1
Sales-type and Direct Financing Leases, Lease Receivables, Gross Difference, Amount [Abstract]
Sales-type and Direct Financing Leases, Lease Receivable	22		22
Sales-type and Direct Financing Leases, Lease Receivable, Undiscounted Excess Amount	(25)		(25)
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
Lessor, Operating Lease, Payment to be Received, Year One	255		255
Lessor, Operating Lease, Payment to be Received, Year Two	475		475
Lessor, Operating Lease, Payment to be Received, Year Three	459		459
Lessor, Operating Lease, Payment to be Received, Year Four	396		396
Lessor, Operating Lease, Payment to be Received, Year Five	396		396
Lessor, Operating Lease, Payment to be Received, after Year Five	1,425		1,425
Lessor, Operating Lease, Payments to be Received	3,406		3,406
Operating Lease, Risk Strategy, Residual Asset	$ 8,623		$ 8,623		$ 8,505