Consolidating Financial Statements (details) - Consolidating Statement of Income (Loss) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Premiums	$ 5,503	$ 5,340	$ 10,874	$ 10,570
Net investment income	758	762	1,537	1,515
Fee income	74	76	148	155
Net realized investment gains (losses)	19	(31)	39	(6)
Other revenues	34	32	68	64
Total revenues	6,388	6,179	12,666	12,298
Claims and claim adjustment expenses	5,141	3,419	8,523	6,807
Amortization of deferred acquisition costs	970	950	1,918	1,879
General and administrative expenses	907	832	1,790	1,679
Interest expense	97	97	193	195
Total claims and expenses	7,115	5,298	12,424	10,560
Income (loss) before income taxes	(727)	881	242	1,738
Income tax expense (benefit)	(363)	211	(233)	421
Net income (loss)	(364)	670	475	1,317
Other-than-temporary impairment losses, total gains	5	2	7	1
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources	(9)	(6)	(15)	(15)
Other-than-temporary impairment losses	(4)	(4)	(8)	(14)
Other net realized investment gains (losses)	23	(27)	47	8
TPC [Member]
Premiums	3,710	3,610	7,335	7,133
Net investment income	511	517	1,043	1,036
Fee income	73	76	147	155
Net realized investment gains (losses)	12	8	21	29
Other revenues	27	27	57	55
Total revenues	4,333	4,238	8,603	8,408
Claims and claim adjustment expenses	3,431	2,277	5,665	4,502
Amortization of deferred acquisition costs	641	629	1,267	1,245
General and administrative expenses	591	566	1,187	1,140
Interest expense	18	19	36	37
Total claims and expenses	4,681	3,491	8,155	6,924
Income (loss) before income taxes	(348)	747	448	1,484
Income tax expense (benefit)	(204)	176	(8)	347
Net income (loss)	(144)	571	456	1,137
Other-than-temporary impairment losses, total gains	(3)	2	(1)	5
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources		(4)	(5)	(10)
Other-than-temporary impairment losses	(3)	(2)	(6)	(5)
Other net realized investment gains (losses)	15	10	27	34
Other Subsidiaries [Member]
Premiums	1,793	1,730	3,539	3,437
Net investment income	245	242	489	473
Fee income	1		1
Net realized investment gains (losses)	11	(25)	23	(11)
Other revenues	7	5	11	9
Total revenues	2,057	1,952	4,063	3,908
Claims and claim adjustment expenses	1,710	1,142	2,858	2,305
Amortization of deferred acquisition costs	329	321	651	634
General and administrative expenses	290	264	580	531
Total claims and expenses	2,329	1,727	4,089	3,470
Income (loss) before income taxes	(272)	225	(26)	438
Income tax expense (benefit)	(126)	66	(69)	115
Net income (loss)	(146)	159	43	323
Other-than-temporary impairment losses, total gains	8		8	(4)
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources	(9)	(2)	(10)	(5)
Other-than-temporary impairment losses	(1)	(2)	(2)	(9)
Other net realized investment gains (losses)	12	(23)	25	(2)
Travelers [Member]
Net investment income	2	3	5	6
Net realized investment gains (losses)	(4)	(14)	(5)	(24)
Total revenues	(2)	(11)		(18)
General and administrative expenses	26	2	23	8
Interest expense	79	78	157	158
Total claims and expenses	105	80	180	166
Income (loss) before income taxes	(107)	(91)	(180)	(184)
Income tax expense (benefit)	(33)	(31)	(156)	(41)
Equity in net income (loss) of subsidiaries	(290)	730	499	1,460
Net income (loss)	(364)	670	475	1,317
Other net realized investment gains (losses)	(4)	(14)	(5)	(24)
Eliminations [Member]
Equity in net income (loss) of subsidiaries	290	(730)	(499)	(1,460)
Net income (loss)	$ 290	$ (730)	$ (499)	$ (1,460)