Benefit Plans (Narrative) (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2022
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, contributions by employer		$ 8,000,000
Pension [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated additional employer contributions		25,000,000
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, contributions by employer		0
Decrease in obligation, pension and other postretirement benefits	$ 432,000,000
Postretirement [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated additional employer contributions		$ 30,000,000