Consolidating Financial Information (Consolidating Statement Of Income Information) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Condensed Financial Statements, Captions [Line Items]
Insurance premiums	$ 1,732	$ 1,645	$ 4,942	$ 4,868
Net investment income	333	654	1,513	1,797
Investment gains (losses)			15	94
Contract drilling revenues	861	749	2,520	2,405
Other	539	591	1,658	1,736
Total			10,648	10,900
Insurance claims and policyholders' benefits	1,400	1,343	4,131	3,798
Amortization of deferred acquisition costs	356	351	1,051	1,038
Contract drilling expenses	392	351	1,142	1,009
Other operating expenses	725	1,271	2,167	2,714
Interest	126	127	406	384
Total	2,999	3,443	8,897	8,943
Income before income tax			1,751	1,957
Income tax (expense) benefit			(464)	(619)
Income from continuing operations	315	174	1,287	1,338
Discontinued operations, net		(22)		(21)
Net income	315	152	1,287	1,317
Amounts attributable to noncontrolling interests	(153)	(116)	(491)	(495)
Net income attributable to Loews Corporation			796	822
CNA Financial [Member]
Condensed Financial Statements, Captions [Line Items]
Insurance premiums			4,942	4,868
Net investment income			1,531	1,692
Investment gains (losses)			14	125
Other			215	226
Total			6,702	6,911
Insurance claims and policyholders' benefits			4,131	3,798
Amortization of deferred acquisition costs			1,051	1,038
Other operating expenses			733	1,319
Interest			142	113
Total			6,057	6,268
Income before income tax			645	643
Income tax (expense) benefit			(201)	(185)
Income from continuing operations				458
Discontinued operations, net				(21)
Net income			444	437
Amounts attributable to noncontrolling interests			(58)	(76)
Net income attributable to Loews Corporation			386	361
Diamond Offshore [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income			4	2
Investment gains (losses)			1
Contract drilling revenues			2,520	2,405
Other			58	111
Total			2,583	2,518
Contract drilling expenses			1,142	1,009
Other operating expenses			406	420
Interest			60	66
Total			1,608	1,495
Income before income tax			975	1,023
Income tax (expense) benefit			(229)	(336)
Income from continuing operations				687
Net income			746	687
Amounts attributable to noncontrolling interests			(383)	(354)
Net income attributable to Loews Corporation			363	333
HighMount [Member]
Condensed Financial Statements, Captions [Line Items]
Investment gains (losses)				(31)
Other			297	351
Total			297	320
Other operating expenses			183	197
Interest			36	49
Total			219	246
Income before income tax			78	74
Income tax (expense) benefit			(28)	(37)
Income from continuing operations				37
Net income			50	37
Net income attributable to Loews Corporation			50	37
Boardwalk Pipeline [Member]
Condensed Financial Statements, Captions [Line Items]
Other			843	821
Total			843	821
Other operating expenses			569	513
Interest			133	112
Total			702	625
Income before income tax			141	196
Income tax (expense) benefit			(35)	(51)
Income from continuing operations				145
Net income			106	145
Amounts attributable to noncontrolling interests			(50)	(65)
Net income attributable to Loews Corporation			56	80
Loews Hotels [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income			1	1
Other			250	229
Total			251	230
Other operating expenses			231	219
Interest			7	7
Total			238	226
Income before income tax			13	4
Income tax (expense) benefit			(5)	(3)
Income from continuing operations				1
Net income			8	1
Net income attributable to Loews Corporation			8	1
Corporate And Other [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income			(23)	102
Intercompany interest and dividends			467	582
Other			(1)	(2)
Total			443	682
Other operating expenses			49	46
Interest			34	43
Total			83	89
Income before income tax			360	593
Income tax (expense) benefit			34	(7)
Income from continuing operations				586
Net income			394	586
Net income attributable to Loews Corporation			394	586
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Intercompany interest and dividends			(467)	(582)
Other			(4)
Total			(471)	(582)
Other operating expenses			(4)
Interest			(6)	(6)
Total			(10)	(6)
Income before income tax			(461)	(576)
Income from continuing operations				(576)
Net income			(461)	(576)
Net income attributable to Loews Corporation			$ (461)	$ (576)