Leases (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease expense	$ 15
Variable lease expense	4
Lease expense	19
Right of use assets	318
Operating lease liabilities	$ 355
Weighted average lease term for lease liabilities	9 years
Weighted average discount rate of remaining payments	3.93%
New Right of Use Assets	$ 4
Cash paid on operating lease liabilities	16
Lease-related revenue	3
Sales-type and Direct Financing Leases, Lease Receivable	$ 320	[1]

[1] Includes unguaranteed residual values of $60 million and excludes net investment in leveraged leases of $215 million.