Leasing (Investments In Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	7 years	7 years
Lessee, operating lease, noncancellable lease term		367 days
Lessee, operating lease, lease extension, maximum		48 months
Operating Lease, Right-of-Use Asset	$ 172	$ 172
Operating Lease, Liability	200	200
Cash paid for amounts included in the measurement of lease liabilities	$ 13	25
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 34
Operating lease, weighted average discount rate	2.97%	2.97%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate		P2Y
Lessor, Operating Lease, Lessee Option to Purchase Underlying Asset		P24M
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate		P5Y
Lessor, Operating Lease, Lessee Option to Purchase Underlying Asset		P60M
Land and Building | Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to Extend		P1Y
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	3 months	3 months
Corporate Facilities | Maximum
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	13 years	13 years
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating Lease, Right-of-Use Asset			$ 161
Operating Lease, Liability			$ 190