Property, Plant and Equipment - DD&A Expense and Capital Expenditures (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
DD&A	$ 955	$ 861	$ 774
Capital Expend.	1,718	2,813	1,755
CNA Financial [Member]
Property, Plant and Equipment [Line Items]
DD&A	74	69	72
Capital Expend.	123	72	90
Diamond Offshore [Member]
Property, Plant and Equipment [Line Items]
DD&A	494	457	389
Capital Expend.	812	2,050	987
Boardwalk Pipeline [Member]
Property, Plant and Equipment [Line Items]
DD&A	327	292	275
Capital Expend.	390	378	305
Loews Hotels [Member]
Property, Plant and Equipment [Line Items]
DD&A	54	37	32
Capital Expend.	389	289	369
Corporate and Other [Member]
Property, Plant and Equipment [Line Items]
DD&A	6	6	6
Capital Expend.	$ 4	$ 24	$ 4