Leases Lessor (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Lessor Disclosure [Abstract]
Operating Lease, Lease Income	$ 154	$ 152	$ 442	$ 460
Variable Lease, Income	24	23	58	59
Lease Income	130	$ 129	384	$ 401
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	126		126
Lessor, Operating Lease, Payment to be Received, Year Two	483		483
Lessor, Operating Lease, Payment to be Received, Year Three	467		467
Lessor, Operating Lease, Payment to be Received, Year Four	403		403
Lessor, Operating Lease, Payment to be Received, Year Five	404		404
Lessor, Operating Lease, Payment to be Received, after Year Five	1,436		1,436
Lessor, Operating Lease, Payments to be Received	3,319		3,319
Operating Lease, Risk Strategy, Residual Asset	$ 8,135		$ 8,135		$ 8,505