Leasing (Investments In Operating Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	7 years
Lessee, operating lease, noncancellable lease term	367 days
Lessee, operating lease, lease extension, maximum	48 months
Operating lease, right-of-use assets	$ 168
Operating lease, liabilities	196
Cash paid for amounts included in the measurement of lease liabilities	49
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 52
Operating lease, weighted average discount rate	2.85%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate	P2Y
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate	P6Y
Land and Building | Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to Extend	P3Y
Land and Building | Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to Extend	P15Y
Corporate Facilities | Minimum
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	8 months
Corporate Facilities | Maximum
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	12 years
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use assets		$ 161
Operating lease, liabilities		$ 190