Claim And Claim Adjustment Expense Reserves (Impact Of The Loss Portfolio Transfer On The Consolidated Statement Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Claim And Claim Adjustment Expense Reserves [Line Items]
Other operating expenses					$ 2,925	$ 3,433	$ 2,972
Income tax expense					536	895	345
Income from continuing operations					1,696	2,007	1,385
Discontinued operations, net						(20)	(2)
Amounts attributable to noncontrolling interests					632	699	819
Net income attributable to Loews Corporation	466	36	366	420	1,064	1,288	564
Loss Portfolio Transfer [Member]
Claim And Claim Adjustment Expense Reserves [Line Items]
Other operating expenses						(529)
Income tax expense						185
Income from continuing operations						(344)
Discontinued operations, net						(21)
Net Loss						(365)
Amounts attributable to noncontrolling interests						37
Net income attributable to Loews Corporation						$ (328)