Property, Plant and Equipment - Depreciation Expense and Capital Expenditures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Depreciation	$ 607	$ 580	$ 534
Capital Expend.	602	585	693
Interest costs capitalized	11	27	32
Operating Segments | CNA Financial
Property, Plant and Equipment [Abstract]
Depreciation	65	59	54
Capital Expend.	73	105	97
Operating Segments | Boardwalk Pipelines
Property, Plant and Equipment [Abstract]
Depreciation	440	426	410
Capital Expend.	386	365	383
Operating Segments | Loews Hotels & Co
Property, Plant and Equipment [Abstract]
Depreciation	100	93	69
Capital Expend.	143	115	201
Corporate | Corporate
Property, Plant and Equipment [Abstract]
Depreciation	2	2	1
Capital Expend.			$ 12