Employee Benefits Schedule of Fair Value, Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Money Market Funds, at Carrying Value	$ 13	$ 7
Equity securities:
Domestic	49	67
Defined Benefit Plan, Plan Assets, Amount		546
Financial Instruments, Owned, at Fair Value	13	7
Other Postretirement Benefit Plans assets: [Abstract]
Money market funds		3
Domestic equity securities - Other postretirement benefit plan assets at fair value		3
International equity securities - other post retirement assets at fair value		8
Private Equity Funds, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Money Market Funds, at Carrying Value	5	5
Investments, Fair Value Disclosure	9	11
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments, Fair Value Disclosure	632	463
Fair Value, Inputs, Level 1 [Member]
Equity securities:
Domestic	49	67
Private equity funds	0	0
Defined Benefit Plan, Plan Assets, Amount	49	67
Financial Instruments, Owned, at Fair Value	43	128
Other Postretirement Benefit Plans assets: [Abstract]
Money market funds	4	3
Domestic equity securities - Other postretirement benefit plan assets at fair value	0	0
International equity securities - other post retirement assets at fair value	9	8
Other post retirement benefit plan assets total	13	11
Fair Value, Inputs, Level 2 [Member]
Equity securities:
Domestic	0	0
Private equity funds	0	0
Defined Benefit Plan, Plan Assets, Amount	0	0
Financial Instruments, Owned, at Fair Value	55	45
Other Postretirement Benefit Plans assets: [Abstract]
Money market funds	0	0
Domestic equity securities - Other postretirement benefit plan assets at fair value	3	3
International equity securities - other post retirement assets at fair value	0	0
Other post retirement benefit plan assets total	8	8
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Money Market Funds, at Carrying Value	0
Equity securities:
Domestic	0	0
Private equity funds	0	0
Defined Benefit Plan, Plan Assets, Amount	0	0
Financial Instruments, Owned, at Fair Value	8	3
Other Postretirement Benefit Plans assets: [Abstract]
Money market funds	0	0
Domestic equity securities - Other postretirement benefit plan assets at fair value	0	0
International equity securities - other post retirement assets at fair value	0	0
Other post retirement benefit plan assets total	0	0
Pension Plan [Member]
Equity securities:
Defined Benefit Plan, Plan Assets, Amount	695	546	$ 629
Financial Instruments, Owned, at Fair Value	646	479
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Money Market Funds, at Carrying Value	5	4
Investments, Fair Value Disclosure	8	7
Equity securities:
Defined Benefit Plan, Plan Assets, Amount	34	30	$ 33
Financial Instruments, Owned, at Fair Value	13	$ 11
Other Postretirement Benefit Plans assets: [Abstract]
Money market funds	4
Domestic equity securities - Other postretirement benefit plan assets at fair value	3
International equity securities - other post retirement assets at fair value	$ 9