Leasing (Investments In Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lessee, operating lease, noncancellable lease term			367 days
Lessee, operating lease, lease extension, maximum			48 months
Operating lease, right-of-use assets	$ 137		$ 137		$ 168
Operating lease, liabilities	163		163		$ 196
Cash paid for amounts included in the measurement of lease liabilities	$ 12	$ 13	25	$ 25
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 43	$ 34
Operating lease, weighted-average remaining lease term	6 years	7 years	6 years	7 years
Operating lease, weighted average discount rate	2.64%	2.97%	2.64%	2.97%
Minimum
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term			2 months
Lessee, operating lease, option to terminate			P2Y
Maximum
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term			9 years
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