Consolidated Condensed Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Common Stock Held in Treasury [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2017	$ 24,566	$ 3	$ 3,151	$ 16,096	$ (26)	$ (20)	$ 5,362
Cumulative effect adjustments from changes in accounting standards at Dec. 31, 2017	(91)			(43)	(28)		(20)
Balance, as adjusted at Dec. 31, 2017	24,475	3	3,151	16,053	(54)	(20)	5,342
Net income	628			523			105
Other comprehensive income	(606)				(542)		(64)
Dividends paid	(140)			(40)			(100)
Purchase of Boardwalk Pipeline common units	(1,715)		661		(29)		(2,347)
Purchases of Loews treasury stock	(788)					(788)
Stock-based compensation	8		1				7
Other	(4)		(4)	(4)			4
Ending Balance at Jun. 30, 2018	21,858	3	3,809	16,532	(625)	(808)	2,947
Beginning Balance at Mar. 31, 2018	23,848	3	3,142	16,321	(417)	(517)	5,316
Net income	248			230			18
Other comprehensive income	(199)				(179)		(20)
Dividends paid	(42)			(20)			(22)
Purchase of Boardwalk Pipeline common units	(1,715)		661		(29)		(2,347)
Purchases of Loews treasury stock	(291)					(291)
Stock-based compensation	8		8
Other	1		(2)	1			2
Ending Balance at Jun. 30, 2018	21,858	3	3,809	16,532	(625)	(808)	2,947
Beginning Balance at Dec. 31, 2018	21,386	3	3,627	15,773	(880)	(5)	2,868
Net income	621			643			(22)
Other comprehensive income	989				883		106
Dividends paid	(116)			(38)			(78)
Purchases of Loews treasury stock	(473)					(473)
Purchases of subsidiary stock from noncontrolling interests	(16)						(16)
Stock-based compensation	8		(13)				21
Other	(5)		(2)	(4)			1
Ending Balance at Jun. 30, 2019	22,394	3	3,612	16,374	3	(478)	2,880
Beginning Balance at Mar. 31, 2019	21,902	3	3,607	16,144	(390)	(327)	2,865
Net income	225			249			(24)
Other comprehensive income	440				393		47
Dividends paid	(29)			(19)			(10)
Purchases of Loews treasury stock	(151)					(151)
Purchases of subsidiary stock from noncontrolling interests	(2)						(2)
Stock-based compensation	7		6				1
Other	2		(1)				3
Ending Balance at Jun. 30, 2019	$ 22,394	$ 3	$ 3,612	$ 16,374	$ 3	$ (478)	$ 2,880