Other Intangibles (Components Of Other Intangibles) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	$ 4,526	$ 4,526
Accumulated Amortization	(3,928)	(3,849)
Net Carrying Amount	598	677
Trade Name [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	122	122
Net Carrying Amount	122	122
Customer Base [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	4,332	4,332
Accumulated Amortization	(3,856)	(3,781)
Net Carrying Amount	476	551
Royalty Agreement [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	72	72
Accumulated Amortization	$ (72)	(68)
Net Carrying Amount		$ 4