Consolidating Financial Statements (details) - Consolidating Statement of Income (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Premiums	$ 5,605	$ 5,422	$ 16,479	$ 15,992
Net investment income	690	735	2,227	2,250
Fee income	79	64	227	219
Net realized investment gains (losses)	2	226	41	220
Other revenues	31	35	99	99
Total revenues	6,407	6,482	19,073	18,780
Claims and claim adjustment expenses	4,136	3,213	12,659	10,020
Amortization of deferred acquisition costs	982	966	2,900	2,845
General and administrative expenses	860	837	2,650	2,516
Interest expense	97	95	290	290
Total claims and expenses	6,075	5,111	18,499	15,671
Income before income taxes	332	1,371	574	3,109
Income tax expense (benefit)	(1)	366	(234)	787
Net income	333	1,005	808	2,322
Other-than-temporary impairment losses, total gains (losses)	9	8	16	9
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources	(21)	(14)	(36)	(29)
Other-than-temporary impairment losses	(12)	(6)	(20)	(20)
Other net realized investment gains (losses)	14	232	61	240
TPC [Member]
Premiums	3,780	3,653	11,115	10,786
Net investment income	460	488	1,503	1,524
Fee income	78	63	225	218
Net realized investment gains (losses)	(13)	8	8	37
Other revenues	24	31	81	86
Total revenues	4,329	4,243	12,932	12,651
Claims and claim adjustment expenses	2,815	2,161	8,480	6,663
Amortization of deferred acquisition costs	654	648	1,921	1,893
General and administrative expenses	579	569	1,766	1,709
Interest expense	19	18	55	55
Total claims and expenses	4,067	3,396	12,222	10,320
Income before income taxes	262	847	710	2,331
Income tax expense (benefit)	8	218		565
Net income	254	629	710	1,766
Other-than-temporary impairment losses, total gains (losses)	13	5	12	10
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources	(19)	(9)	(24)	(19)
Other-than-temporary impairment losses	(6)	(4)	(12)	(9)
Other net realized investment gains (losses)	(7)	12	20	46
Other Subsidiaries [Member]
Premiums	1,825	1,769	5,364	5,206
Net investment income	228	244	717	717
Fee income	1	1	2	1
Net realized investment gains (losses)	15	188	38	177
Other revenues	7	5	18	14
Total revenues	2,076	2,207	6,139	6,115
Claims and claim adjustment expenses	1,321	1,052	4,179	3,357
Amortization of deferred acquisition costs	328	318	979	952
General and administrative expenses	279	265	859	796
Total claims and expenses	1,928	1,635	6,017	5,105
Income before income taxes	148	572	122	1,010
Income tax expense (benefit)	18	158	(51)	273
Net income	130	414	173	737
Other-than-temporary impairment losses, total gains (losses)	(4)	3	4	(1)
Other-than-temporary impairment losses, non-credit component of impairments recognized in accumulated other changes in equity from nonowner sources	(2)	(5)	(12)	(10)
Other-than-temporary impairment losses	(6)	(2)	(8)	(11)
Other net realized investment gains (losses)	21	190	46	188
Travelers [Member]
Net investment income	2	3	7	9
Net realized investment gains (losses)		30	(5)	6
Total revenues	2	33	2	15
General and administrative expenses	2	3	25	11
Interest expense	78	78	235	236
Total claims and expenses	80	81	260	247
Income before income taxes	(78)	(48)	(258)	(232)
Income tax expense (benefit)	(27)	(10)	(183)	(51)
Equity in net income of subsidiaries	384	1,043	883	2,503
Net income	333	1,005	808	2,322
Other net realized investment gains (losses)		30	(5)	6
Eliminations [Member]
Other revenues		(1)		(1)
Total revenues		(1)		(1)
Interest expense		(1)		(1)
Total claims and expenses		(1)		(1)
Equity in net income of subsidiaries	(384)	(1,043)	(883)	(2,503)
Net income	$ (384)	$ (1,043)	$ (883)	$ (2,503)