Consolidating Financial Statements (details) - Consolidating Statement of Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Consolidating Statement of Income
Premiums	$ 5,888		$ 5,823
Net investment income	592		736
Fee income	111		107
Net realized investment gains (losses)	10	[1]	1	[1]
Other revenues	25		41
Total revenues	6,626		6,708
Claims and claim adjustment expenses	3,431		3,315
Amortization of deferred acquisition costs	963		950
General and administrative expenses	992		881
Interest expense	92		92
Total claims and expenses	5,478		5,238
Income before income taxes	1,148		1,470
Income tax expense (benefit)	315		418
Net income	833		1,052
Total other-than-temporary impairment losses	(4)		(7)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(3)		(9)
Other-than-temporary impairment gains (losses) recognized in OCI	(1)		2
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Income
Premiums	3,996		3,944
Net investment income	411		500
Fee income	111		107
Net realized investment gains (losses)	2		1
Other revenues	21		33
Total revenues	4,541		4,585
Claims and claim adjustment expenses	2,309		2,221
Amortization of deferred acquisition costs	642		635
General and administrative expenses	695		613
Interest expense	12		12
Total claims and expenses	3,658		3,481
Income before income taxes	883		1,104
Income tax expense (benefit)	251		321
Net income	632		783
Total other-than-temporary impairment losses	(1)		(2)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(1)		(4)
Other-than-temporary impairment gains (losses) recognized in OCI			2
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Income
Premiums	1,892		1,879
Net investment income	180		235
Net realized investment gains (losses)	7		(2)
Other revenues	4		8
Total revenues	2,083		2,120
Claims and claim adjustment expenses	1,122		1,094
Amortization of deferred acquisition costs	321		315
General and administrative expenses	292		265
Total claims and expenses	1,735		1,674
Income before income taxes	348		446
Income tax expense (benefit)	93		125
Net income	255		321
Total other-than-temporary impairment losses	(3)		(5)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(2)		(5)
Other-than-temporary impairment gains (losses) recognized in OCI	(1)
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Statement of Income
Net investment income	1		1
Net realized investment gains (losses)	1		2
Total revenues	2		3
General and administrative expenses	5		3
Interest expense	80		80
Total claims and expenses	85		83
Income before income taxes	(83)		(80)
Income tax expense (benefit)	(29)		(28)
Net income of subsidiaries	887		1,104
Net income	833		1,052
Eliminations [Member]
Consolidating Statement of Income
Net income of subsidiaries	(887)		(1,104)
Net income	$ (887)		$ (1,104)

[1] Total other-than-temporary impairment (OTTI) losses were $(4) million and $(7) million for the three months ended March 31, 2015 and 2014, respectively. Of total OTTI, credit losses of $(3) million and $(9) million for the three months ended March 31, 2015 and 2014, respectively, were recognized in net realized investment gains. In addition, unrealized gains (losses) from other changes in total OTTI of $(1) million and $2 million for the three months ended March 31, 2015 and 2014, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.