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No definition available.

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- Definition

Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

+ References

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-Publisher FASB
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- Definition

Amount of net periodic benefit cost (credit) for defined benefit plan.

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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

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Benefit Plans and Other Postretirement Benefits, Postretirement Health Care Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Total benefit obligation	$ 64	$ 73	$ 76
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 1	$ 0	$ 2
Target pension asset allocations (as a percent)	100.00%	100.00%
Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan
Postretirement Health Care Benefits [Abstract]
Total benefit obligation	$ 3	$ 4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		1
Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan \| Parent Company [Member]
Postretirement Health Care Benefits [Abstract]
Total benefit obligation	43	43
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 4	$ 6
Domestic and international equity securities \| Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	15.00%	15.00%
Long-duration fixed income and interest rate swap securities \| Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	0.00%	0.00%
Short-to-intermediate fixed income securities \| Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	71.00%	72.00%
Alternative investments \| Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	8.00%	9.00%
Cash \| Postretirement Benefits Plan
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	6.00%	4.00%