Consolidating Financial Statements (details) - Consolidating Statement of Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Consolidating Statement of Income (Loss)
Premiums	$ 5,603		$ 5,529		$ 11,120		$ 11,052
Net investment income	687		738		1,357		1,478
Fee income	82		59		179		141
Net realized investment gains (losses)	167	[1]	4	[1]	177	[1]	14	[1]
Other revenues	135		29		169		66
Total revenues	6,674		6,359		13,002		12,751
Claims and claim adjustment expenses	3,530		3,786		6,683		7,150
Amortization of deferred acquisition costs	950		976		1,898		1,947
General and administrative expenses	931		893		1,846		1,777
Interest expense	86		96		178		192
Total claims and expenses	5,497		5,751		10,605		11,066
Income before income taxes	1,177		608		2,397		1,685
Income tax expense (benefit)	252		109		576		380
Net income	925		499		1,821		1,305
Total other-than-temporary impairment gains (losses)	(1)		11		(1)		11
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(2)		(4)		(7)		(8)
Other-than-temporary impairment gains recognized in other comprehensive income	1		15		6		19
TPC [Member]
Consolidating Statement of Income (Loss)
Premiums	3,804		3,745		7,545		7,488
Net investment income	457		507		912		1,001
Fee income	82		58		178		140
Net realized investment gains (losses)	124		3		117		15
Other revenues	103		22		132		49
Total revenues	4,570		4,335		8,884		8,693
Claims and claim adjustment expenses	2,339		2,549		4,470		4,821
Amortization of deferred acquisition costs	635		647		1,272		1,293
General and administrative expenses	639		608		1,269		1,207
Interest expense	12		18		29		36
Total claims and expenses	3,625		3,822		7,040		7,357
Income before income taxes	945		513		1,844		1,336
Income tax expense (benefit)	203		119		452		324
Net income	742		394		1,392		1,012
Total other-than-temporary impairment gains (losses)	(1)		(1)		(4)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(1)		(3)		(5)		(6)
Other-than-temporary impairment gains recognized in other comprehensive income			2		1		6
Other Subsidiaries [Member]
Consolidating Statement of Income (Loss)
Premiums	1,799		1,784		3,575		3,564
Net investment income	229		229		442		473
Fee income			1		1		1
Net realized investment gains (losses)	43		1		59		(1)
Other revenues	32		7		37		17
Total revenues	2,103		2,022		4,114		4,054
Claims and claim adjustment expenses	1,191		1,237		2,213		2,329
Amortization of deferred acquisition costs	315		329		626		654
General and administrative expenses	289		284		575		566
Total claims and expenses	1,795		1,850		3,414		3,549
Income before income taxes	308		172		700		505
Income tax expense (benefit)	77		27		176		111
Net income	231		145		524		394
Total other-than-temporary impairment gains (losses)			12		3		11
Other-than-temporary impairment losses recognized in net realized investment gains (losses)	(1)		(1)		(2)		(2)
Other-than-temporary impairment gains recognized in other comprehensive income	1		13		5		13
Travelers [Member]
Consolidating Statement of Income (Loss)
Net investment income	1		2		3		4
Net realized investment gains (losses)					1
Total revenues	1		2		4		4
General and administrative expenses	3		1		2		4
Interest expense	74		78		149		156
Total claims and expenses	77		79		151		160
Income before income taxes	(76)		(77)		(147)		(156)
Income tax expense (benefit)	(28)		(37)		(52)		(55)
Net income of subsidiaries	973		539		1,916		1,406
Net income	925		499		1,821		1,305
Eliminations [Member]
Consolidating Statement of Income (Loss)
Net income of subsidiaries	(973)		(539)		(1,916)		(1,406)
Net income	$ (973)		$ (539)		$ (1,916)		$ (1,406)

[1] Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $11 million for the three months ended June 30, 2013 and 2012, respectively, and $(1) million and $11 million for the six months ended June 30, 2013 and 2012, respectively. Of total OTTI, credit losses of $(2) million and $(4) million for the three months ended June 30, 2013 and 2012, respectively, and $(7) million and $(8) million for the six months ended June 30, 2013 and 2012, respectively, were recognized in net realized investment gains. In addition, unrealized gains from other changes in total OTTI of $1 million and $15 million for the three months ended June 30, 2013 and 2012, respectively, and $6 million and $19 million for the six months ended June 30, 2013 and 2012, respectively, were recognized in other comprehensive income as part of change in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.