Employee Benefits Schedule of Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$ 52
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	52
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	54
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	55
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	54
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	273
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	45
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	45
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	46
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	47
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	47
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	243
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	6
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	5
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	19
Non Qualified Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	3
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	2
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 11