Leases (Contractual Maturities of Operating Lease Liabilities) (Details) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 60
Lessee, Operating Lease, Liability, Payments, Due Year Two	62
Lessee, Operating Lease, Liability, Payments, Due Year Three	53
Lessee, Operating Lease, Liability, Payments, Due Year Four	46
Lessee, Operating Lease, Liability, Payments, Due Year Five	42
Lessee, Operating Lease, Liability, Payments, Due after Year Five	175
Lessee, Operating Lease, Liability, Payments, Due	438
Operating lease imputed interest	(71)
Operating lease liabilities	$ 367