Benefit Plans and Other Postretirement Benefits, Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Pension Plan [Member]
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets			$ 397	[1]	$ 420	[1]	$ 417
Total benefit obligation			409		425		414
Net benefit cost recognized for financial reporting			$ (1)		$ 4		$ 6
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets			6.97%		6.96%		6.39%
Pension Plan [Member] | Forecast [Member]
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets For Next Fiscal Year		7.03%
Pension Plan [Member] | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		$ 23		$ 115
Pension Plan [Member] | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		114		114
Pension Plan [Member] | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		1		1
Pension Plan [Member] | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		259		190
Pension Plan [Member] | Cash equivalents
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		19		38
Pension Plan [Member] | Cash equivalents | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		19		38
Pension Plan [Member] | Cash equivalents | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Cash equivalents | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Cash equivalents | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Pension Plan [Member] | Commingled funds
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		259		262
Pension Plan [Member] | Commingled funds | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		72
Pension Plan [Member] | Commingled funds | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Commingled funds | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Commingled funds | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		259		190
Pension Plan [Member] | Debt securities
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		114		117
Pension Plan [Member] | Debt securities | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Debt securities | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		113		116
Pension Plan [Member] | Debt securities | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		1		1
Pension Plan [Member] | Debt securities | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Pension Plan [Member] | Equity securities
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		5
Pension Plan [Member] | Equity securities | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		5
Pension Plan [Member] | Equity securities | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Equity securities | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Equity securities | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Pension Plan [Member] | Other Investments [Member]
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		1		(2)
Pension Plan [Member] | Other Investments [Member] | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Other Investments [Member] | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		1		(2)
Pension Plan [Member] | Other Investments [Member] | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Pension Plan [Member] | Other Investments [Member] | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Other Postretirement Benefits Plan [Member]
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets			36	[1]	36	[1]	$ 36
Total benefit obligation			26		26		26
Net benefit cost recognized for financial reporting			$ 0		$ 1		$ 0
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets			5.00%		5.00%		4.10%
Other Postretirement Benefits Plan [Member] | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		$ 4		$ 5
Other Postretirement Benefits Plan [Member] | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		25		24
Other Postretirement Benefits Plan [Member] | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		7		7
Other Postretirement Benefits Plan [Member] | Cash equivalents
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		3
Other Postretirement Benefits Plan [Member] | Cash equivalents | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		3
Other Postretirement Benefits Plan [Member] | Cash equivalents | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Cash equivalents | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Cash equivalents | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Other Postretirement Benefits Plan [Member] | Insurance contracts
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		5
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		4		5
Other Postretirement Benefits Plan [Member] | Insurance contracts | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Insurance contracts | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Other Postretirement Benefits Plan [Member] | Commingled funds
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		7		9
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		2
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Commingled funds | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Commingled funds | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		7		7
Other Postretirement Benefits Plan [Member] | Debt securities
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		21		19
Other Postretirement Benefits Plan [Member] | Debt securities | Level 1
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Debt securities | Level 2
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		21		19
Other Postretirement Benefits Plan [Member] | Debt securities | Level 3
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Fair value of plan assets	[1]		0		0
Other Postretirement Benefits Plan [Member] | Debt securities | Fair Value Measured at Net Asset Value Per Share
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Plan asset investments measured at net asset value	[1]		0		0
Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan | Parent Company [Member]
Plan Assets Measured at Fair Value for Each of the Fair Value Hierarchy Levels [Abstract]
Total benefit obligation			$ 13		$ 12

[1] See Note 8 for further information on fair value measurement inputs and methods.