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]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2010 (Scenario, Previously Reported [Member])	$ 23,106	$ 4	$ 3,667	$ 14,564	$ 230	$ (15)	$ 4,656
Balance at Dec. 31, 2010	23,028	4	3,667	14,500	230	(15)	4,642
Adjustment to initially apply updated guidance on accounting for costs associated with acquiring or renewing insurance contracts (Restatement Adjustment [Member])	(78)			(64)			(14)
Net income	1,282			791			491
Other comprehensive income	552				496		56
Dividends paid	(373)			(76)			(297)
Acquisition of CNA Surety noncontrolling interests	(475)		(59)		17		(433)
Issuance of equity securities by subsidiary	152		28		1		123
Purchase of Loews treasury stock	(690)					(690)
Issuance of Loews common stock	4		4
Stock-based compensation	16		14				2
Other	(6)		(1)	(2)			(3)
Balance at Sep. 30, 2011	23,490	4	3,653	15,213	744	(705)	4,581
Balance at Dec. 31, 2011 (Scenario, Previously Reported [Member])	23,273	4	3,499	14,957	375		4,438
Balance at Dec. 31, 2011	23,203	4	3,494	14,890	384		4,431
Adjustment to initially apply updated guidance on accounting for costs associated with acquiring or renewing insurance contracts (Restatement Adjustment [Member])	(70)		(5)	(67)	9		(7)
Net income	1,027			600			427
Other comprehensive income	643				577		66
Dividends paid	(404)			(74)			(330)
Issuance of equity securities by subsidiary	508		79		3		426
Purchase of Loews treasury stock	(139)					(139)
Issuance of Loews common stock	9		9
Stock-based compensation	17		15				2
Other	(2)		(2)	(1)			1
Balance at Sep. 30, 2012	$ 24,862	$ 4	$ 3,595	$ 15,415	$ 964	$ (139)	$ 5,023