CONSOLIDATED CONDENSED STATEMENTS OF EQUITY (Unaudited) - 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]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Common Stock Held in Treasury [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Noncontrolling Interests [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]
Balance at Dec. 31, 2018	$ 21,386	$ 3	$ 3,627	$ 15,773	$ (880)	$ (5)	$ 2,868
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)	660			715			(55)
Other comprehensive income	1,005				897		108
Dividends paid	(145)			(57)
Dividends paid							(88)
Purchases of Loews Corporation treasury stock	(642)					(642)
Purchases of subsidiary stock from noncontrolling interests	(18)						(18)
Stock-based compensation	17		(5)				22
Other	(5)		(2)	(4)			1
Balance at Sep. 30, 2019	22,258	3	3,620	16,427	17	(647)	2,838
Balance at Jun. 30, 2019	22,394	3	3,612	16,374	3	(478)	2,880
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)	39			72			(33)
Other comprehensive income	16				14		2
Dividends paid	(29)			(19)
Dividends paid							(10)
Purchases of Loews Corporation treasury stock	(169)					(169)
Purchases of subsidiary stock from noncontrolling interests	(2)						(2)
Stock-based compensation	9		8				1
Balance at Sep. 30, 2019	22,258	3	3,620	16,427	17	(647)	2,838
Balance at Dec. 31, 2019	21,930	3	3,374	15,823	(68)	(13)	2,811	$ 21,925	$ 3	$ 3,374	$ 15,818	$ (68)	$ (13)	$ 2,811
Balance (ASU 2016-13 [Member]) at Dec. 31, 2019															$ (5)	$ (5)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)	(1,728)			(1,328)			(400)
Other comprehensive income	343				306		37
Dividends paid	(141)			(53)
Dividends paid							(88)
Deconsolidation of Diamond Offshore	(1,087)						(1,087)
Purchases of Loews Corporation treasury stock	(673)					(673)
Purchases of subsidiary stock from noncontrolling interests	(37)		5				(42)
Stock-based compensation	17		(1)				18
Other	1		1			1	(1)
Balance at Sep. 30, 2020	18,620	3	3,379	14,437	238	(685)	1,248
Balance at Jun. 30, 2020	18,413	3	3,371	14,316	5	(491)	1,209
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income (loss)	162			139			23
Other comprehensive income	259				233		26
Dividends paid	(27)			(17)
Dividends paid							(10)
Purchases of Loews Corporation treasury stock	(195)					(195)
Stock-based compensation	8		8
Other	0			(1)		1
Balance at Sep. 30, 2020	$ 18,620	$ 3	$ 3,379	$ 14,437	$ 238	$ (685)	$ 1,248