Leases (Future lease payments) (Details)	Dec. 31, 2019 USD ($)
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 242,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Two	217,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Three	168,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Four	116,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Five	71,000,000
Lessee, Operating Lease, Liability, Payments, Due after Year Five	238,000,000
Lessee, Operating Lease, Liability, Payments, Due	1,052,000,000
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(133,000,000)
Total lease liabilities	919,000,000
Lessee, Operating Lease, Lease Not Yet Commenced, Amount	$ 0