Consolidating Financial Statements (details) - Consolidating Statement of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidating Statement of Comprehensive Income
Net income	$ 806	$ 839
Change in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(77)	(106)
Change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	25	28
Net changes in benefit plan assets and obligations	20	18
Net changes in unrealized foreign currency translation and other changes	64	70
Other comprehensive income before income taxes	32	10
Income tax benefit, other comprehensive income	(2)	(7)
Other comprehensive income, net of taxes	34	17
Comprehensive income	840	856
TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	618	600
Change in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(54)	(70)
Change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	16	10
Net changes in unrealized foreign currency translation and other changes	21	22
Other comprehensive income before income taxes	(17)	(38)
Income tax benefit, other comprehensive income	(7)	(14)
Other comprehensive income, net of taxes	(10)	(24)
Comprehensive income	608	576
Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	249	189
Change in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(32)	(39)
Change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	9	18
Net changes in benefit plan assets and obligations	(1)
Net changes in unrealized foreign currency translation and other changes	43	47
Other comprehensive income before income taxes	19	26
Income tax benefit, other comprehensive income	(5)	(1)
Other comprehensive income, net of taxes	24	27
Comprehensive income	273	216
Travelers [Member]
Consolidating Statement of Comprehensive Income
Net income	806	839
Change in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(77)	(106)
Change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	25	28
Net changes in benefit plan assets and obligations	20	18
Net changes in unrealized foreign currency translation and other changes	64	70
Other comprehensive income before income taxes	32	10
Income tax benefit, other comprehensive income	(2)	(7)
Other comprehensive income, net of taxes	34	17
Comprehensive income	840	856
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(867)	(789)
Change in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	86	109
Change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(25)	(28)
Net changes in benefit plan assets and obligations	1
Net changes in unrealized foreign currency translation and other changes	(64)	(69)
Other comprehensive income before income taxes	(2)	12
Income tax benefit, other comprehensive income	12	15
Other comprehensive income, net of taxes	(14)	(3)
Comprehensive income	$ (881)	$ (792)