Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred tax liabilities:
Property, plant and equipment	$ (1,623)	$ (1,524)
Intangible assets	(90)	(83)
Other	(52)	(40)
Total deferred tax liabilities	(1,765)	(1,647)
Deferred tax assets:
Payable to affiliate due to post-retirement benefit plan participation	306	312
Other	0	1
Gross deferred tax assets	306	313
Net deferred tax assets	306	313
Net deferred tax liabilities	$ (1,459)	$ (1,334)