Consolidating Financial Statements (details) - Consolidating Statement of Income (Unaudited) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidating Statement of Income
Premiums										$ 23,874	$ 23,713	$ 22,637
Net investment income										2,379	2,787	2,716
Fee income										445	438	395
Net realized investment gains (losses)	[1]									3	79	166
Other revenues										99	145	277
Total revenues		$ 6,674	$ 6,794	$ 6,706	$ 6,626	$ 6,783	$ 6,886	$ 6,785	$ 6,708	26,800	27,162	26,191
Claims and claim adjustment expenses										13,723	13,870	13,307
Amortization of deferred acquisition costs										3,885	3,882	3,821
General and administrative expenses										4,079	3,952	3,757
Interest expense										373	369	361
Total claims and expenses		5,465	5,487	5,630	5,478	5,323	5,628	5,884	5,238	22,060	22,073	21,246
Income before income taxes		1,209	1,307	1,076	1,148	1,460	1,258	901	1,470	4,740	5,089	4,945
Income tax expense (benefit)		343	379	264	315	422	339	218	418	1,301	1,397	1,272
Net income		$ 866	$ 928	$ 812	$ 833	$ 1,038	$ 919	$ 683	$ 1,052	3,439	3,692	3,673
Total other-than-temporary impairment losses										(54)	(22)	(10)
Other-than-temporary impairment losses recognized in net realized investment gains										(52)	(26)	(15)
Other-than-temporary impairment gains (losses) recognized in other comprehensive income										(2)	4	5
TPC [Member]
Consolidating Statement of Income
Premiums										16,254	16,097	15,262
Net investment income										1,612	1,874	1,830
Fee income										445	436	393
Net realized investment gains (losses)										13	12	126
Other revenues										78	125	225
Total revenues										18,402	18,544	17,836
Claims and claim adjustment expenses										9,208	9,274	8,817
Amortization of deferred acquisition costs										2,627	2,604	2,571
General and administrative expenses										2,838	2,743	2,570
Interest expense										48	48	53
Total claims and expenses										14,721	14,669	14,011
Income before income taxes										3,681	3,875	3,825
Income tax expense (benefit)										1,015	1,095	1,054
Net income										2,666	2,780	2,771
Total other-than-temporary impairment losses										(19)	(16)	(8)
Other-than-temporary impairment losses recognized in net realized investment gains										(18)	(19)	(10)
Other-than-temporary impairment gains (losses) recognized in other comprehensive income										(1)	3	2
Other Subsidiaries [Member]
Consolidating Statement of Income
Premiums										7,620	7,616	7,375
Net investment income										760	907	879
Fee income											2	2
Net realized investment gains (losses)										(11)	64	38
Other revenues										21	20	52
Total revenues										8,390	8,609	8,346
Claims and claim adjustment expenses										4,515	4,596	4,490
Amortization of deferred acquisition costs										1,258	1,278	1,250
General and administrative expenses										1,225	1,194	1,174
Total claims and expenses										6,998	7,068	6,914
Income before income taxes										1,392	1,541	1,432
Income tax expense (benefit)										394	417	388
Net income										998	1,124	1,044
Total other-than-temporary impairment losses										(35)	(6)	(2)
Other-than-temporary impairment losses recognized in net realized investment gains										(34)	(7)	(5)
Other-than-temporary impairment gains (losses) recognized in other comprehensive income										(1)	1	3
Travelers [Member]
Consolidating Statement of Income
Net investment income										7	6	7
Net realized investment gains (losses)										1	3	2
Total revenues										8	9	9
General and administrative expenses										16	15	13
Interest expense										325	321	308
Total claims and expenses										341	336	321
Income before income taxes										(333)	(327)	(312)
Income tax expense (benefit)										(108)	(115)	(170)
Net income of subsidiaries										3,664	3,904	3,815
Net income										3,439	3,692	3,673
Other-than-temporary impairment losses recognized in net realized investment gains										0	0	0
Other-than-temporary impairment gains (losses) recognized in other comprehensive income										0	0	0
Eliminations [Member]
Consolidating Statement of Income
Net income of subsidiaries										(3,664)	(3,904)	(3,815)
Net income										$ (3,664)	$ (3,904)	$ (3,815)

[1] Total other-than-temporary impairment (OTTI) losses were $(54) million, $(22) million and $(10) million for the years ended December 31, 2015, 2014 and 2013, respectively. Of total OTTI, credit losses of $(52) million, $(26) million and $(15) million for the years ended December 31, 2015, 2014 and 2013, respectively, were recognized in net realized investment gains. In addition, unrealized gains (losses) from other changes in total OTTI of $(2) million, $4 million and $5 million for the years ended December 31, 2015, 2014 and 2013, 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.