Consolidating Financial Statements (details) - Consolidated Statement of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Consolidating Statement of Comprehensive Income
Net income	$ 864	$ 864	$ 2,685	$ 2,169
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(204)	470	(2,370)	609
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(2)	41	2	71
Net changes in benefit plan assets and obligations	24	22	78	64
Net changes in unrealized foreign currency translation	112	65	(57)	43
Other comprehensive income (loss) before income taxes	(70)	598	(2,347)	787
Income tax expense (benefit)	(55)	192	(816)	256
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(15)	406	(1,531)	531
Other comprehensive income (loss), net of taxes	(15)	406	(1,531)	531
Comprehensive income	849	1,270	1,154	2,700
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	664	598	2,056	1,610
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(138)	338	(1,735)	451
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(1)	28	4	49
Net changes in benefit plan assets and obligations		1	1	1
Net changes in unrealized foreign currency translation	26	13	(35)	(20)
Other comprehensive income (loss) before income taxes	(113)	380	(1,765)	481
Income tax expense (benefit)	(46)	129	(616)	165
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(67)	251	(1,149)	316
Other comprehensive income (loss), net of taxes	(67)	251	(1,149)	316
Comprehensive income	597	849	907	1,926
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	251	310	775	704
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(71)	127	(647)	147
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(1)	13	(2)	22
Net changes in benefit plan assets and obligations	(1)		2
Net changes in unrealized foreign currency translation	86	52	(22)	63
Other comprehensive income (loss) before income taxes	13	192	(669)	232
Income tax expense (benefit)	(20)	54	(231)	65
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	33	138	(438)	167
Other comprehensive income (loss), net of taxes	33	138	(438)	167
Comprehensive income	284	448	337	871
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Statement of Comprehensive Income
Net income	864	864	2,685	2,169
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	5	5	12	11
Net changes in benefit plan assets and obligations	25	21	75	63
Other comprehensive income (loss) before income taxes	30	26	87	74
Income tax expense (benefit)	11	9	31	26
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	19	17	56	48
Other comprehensive income (loss) of subsidiaries	(34)	389	(1,587)	483
Other comprehensive income (loss), net of taxes	(15)	406	(1,531)	531
Comprehensive income	849	1,270	1,154	2,700
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(915)	(908)	(2,831)	(2,314)
Other comprehensive income (loss) of subsidiaries	34	(389)	1,587	(483)
Other comprehensive income (loss), net of taxes	34	(389)	1,587	(483)
Comprehensive income	$ (881)	$ (1,297)	$ (1,244)	$ (2,797)