Employee Benefit Plans (Components of Net Periodic Benefit Cost Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	$ (2)	$ (23)	$ 1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	1	1	1
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	14	13	13
Defined Benefit Plan, Interest Cost	6	7	5
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(9)	(7)	(8)
Defined Benefit Plan, Amortization of Gain (Loss)	5	4	4
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost, Total	16	17	14
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	17	14	13
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	(5)	(4)	(4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0	0	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	0	0	0
Other Comprehensive Income Defined Benefit Plan Net Foreign Exchange Translations And Other Adjustments	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	12	10	9
Defined Benefit Plan Net Periodic Benefit Cost And Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase Decrease	28	27	23
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	3	3	3
Defined Benefit Plan, Interest Cost	2	3	2
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	2	1	2
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost, Total	6	6	6
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax	(8)	14	(7)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	(2)	(1)	(2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	1	1	1
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	0	0	0
Other Comprehensive Income Defined Benefit Plan Net Foreign Exchange Translations And Other Adjustments	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	(9)	14	(8)
Defined Benefit Plan Net Periodic Benefit Cost And Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase Decrease	$ (3)	$ 20	$ (2)