Consolidating Financial Statements (details) - Consolidated Statement of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidating Statement of Comprehensive Income
Net income	$ 919	$ 864	$ 2,654	$ 2,685
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(154)	(204)	901	(2,370)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	1	(2)	4	2
Net changes in benefit plan assets and obligations	15	24	45	78
Net changes in unrealized foreign currency translation	(203)	112	(149)	(57)
Other comprehensive income (loss) before income taxes	(341)	(70)	801	(2,347)
Income tax expense (benefit)	(79)	(55)	311	(816)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(262)	(15)	490	(1,531)
Other comprehensive income (loss), net of taxes	(262)	(15)	490	(1,531)
Comprehensive income	657	849	3,144	1,154
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	687	664	1,996	2,056
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(118)	(138)	632	(1,735)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	2	(1)	11	4
Net changes in benefit plan assets and obligations				1
Net changes in unrealized foreign currency translation	(120)	26	(94)	(35)
Other comprehensive income (loss) before income taxes	(236)	(113)	549	(1,765)
Income tax expense (benefit)	(62)	(46)	210	(616)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(174)	(67)	339	(1,149)
Other comprehensive income (loss), net of taxes	(174)	(67)	339	(1,149)
Comprehensive income	513	597	2,335	907
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	285	251	817	775
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(35)	(71)	266	(647)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(1)	(1)	(7)	(2)
Net changes in benefit plan assets and obligations	1	(1)	1	2
Net changes in unrealized foreign currency translation	(83)	86	(55)	(22)
Other comprehensive income (loss) before income taxes	(118)	13	205	(669)
Income tax expense (benefit)	(22)	(20)	84	(231)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(96)	33	121	(438)
Other comprehensive income (loss), net of taxes	(96)	33	121	(438)
Comprehensive income	189	284	938	337
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Statement of Comprehensive Income
Net income	919	864	2,654	2,685
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(1)	5	3	12
Net changes in benefit plan assets and obligations	14	25	44	75
Other comprehensive income (loss) before income taxes	13	30	47	87
Income tax expense (benefit)	5	11	17	31
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	8	19	30	56
Other comprehensive income (loss) of subsidiaries	(270)	(34)	460	(1,587)
Other comprehensive income (loss), net of taxes	(262)	(15)	490	(1,531)
Comprehensive income	657	849	3,144	1,154
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(972)	(915)	(2,813)	(2,831)
Other comprehensive income (loss) of subsidiaries	270	34	(460)	1,587
Other comprehensive income (loss), net of taxes	270	34	(460)	1,587
Comprehensive income	$ (702)	$ (881)	$ (3,273)	$ (1,244)