Goodwill And Other Intangibles (Components Of Other Intangibles) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,526	$ 4,526
Accumulated Amortization	(3,605)	(3,506)
Net Carrying Amount	921	1,020
Customer Base [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,332	4,332
Accumulated Amortization	(3,547)	(3,452)
Net Carrying Amount	785	880
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	122	122
Net Carrying Amount	122	122
Royalty Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	72	72
Accumulated Amortization	(58)	(54)
Net Carrying Amount	$ 14	$ 18