Consolidating Financial Statements (details) - Consolidating Balance Sheet (Unaudited) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	$ 63,474	$ 63,956
Equity securities, available for sale, at fair value	899	943
Real estate investments	938	938
Short-term securities	4,364	3,882
Other investments	3,586	3,441
Total investments	73,261	73,160
Cash	374	294	330	214
Investment income accrued	685	734
Premiums receivable	6,298	6,125
Reinsurance recoverables	9,260	9,713
Ceded unearned premiums	678	801
Deferred acquisition costs	1,835	1,804	1,792
Deferred taxes	33	303
Contractholder receivables	4,362	4,328
Goodwill	3,611	3,634
Other intangible assets	304	351
Other assets	2,377	2,565
Total assets	103,078	103,812
Claims and claim adjustment expense reserves	49,850	50,895	50,922
Unearned premium reserves	11,839	11,850	11,241
Contractholder payables	4,362	4,328
Payables for reinsurance premiums	336	298
Debt	6,349	6,346
Other liabilities	5,506	5,299
Total liabilities	78,242	79,016
Common stock	21,843	21,500	21,161	20,732
Retained earnings	27,251	24,291	21,352	19,579
Accumulated other comprehensive income	880	810	2,236	2,005
Treasury stock, at cost	(25,138)	(21,805)	(19,344)	(17,839)
Total shareholders' equity	24,836	24,796	25,405
Total liabilities and shareholders' equity	103,078	103,812
Fixed maturities, available for sale, amortized cost	60,801	62,196
Equity securities, available for sale, cost	579	686
Common stock, shares authorized	1,750.0	1,750.0
Common stock, shares issued	322.2	353.5
Common stock, shares outstanding	322.2	353.5	377.4	392.8
Treasury stock, at cost, shares	437.3	401.5
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	43,401	43,720
Equity securities, available for sale, at fair value	236	329
Real estate investments	56	33
Short-term securities	2,128	1,867
Other investments	2,630	2,450
Total investments	48,451	48,399
Cash	221	137	177	114
Investment income accrued	468	499
Premiums receivable	4,241	4,124
Reinsurance recoverables	6,156	6,292
Ceded unearned premiums	608	712
Deferred acquisition costs	1,622	1,570
Deferred taxes	23	279
Contractholder receivables	3,306	3,179
Goodwill	2,602	2,619
Other intangible assets	216	250
Other assets	1,931	2,010
Total assets	69,845	70,070
Claims and claim adjustment expense reserves	32,999	33,506
Unearned premium reserves	8,201	8,188
Contractholder payables	3,306	3,179
Payables for reinsurance premiums	194	127
Debt	692	692
Other liabilities	4,084	4,109
Total liabilities	49,476	49,801
Additional paid-in capital	11,634	11,634
Retained earnings	7,673	7,868
Accumulated other comprehensive income	1,062	767
Total shareholders' equity	20,369	20,269
Total liabilities and shareholders' equity	69,845	70,070
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	20,043	20,199
Equity securities, available for sale, at fair value	522	484
Real estate investments	882	905
Short-term securities	706	492
Other investments	955	990
Total investments	23,108	23,070
Cash	151	154	151	98
Investment income accrued	215	231
Premiums receivable	2,057	2,001
Reinsurance recoverables	3,104	3,421
Ceded unearned premiums	70	89
Deferred acquisition costs	213	234
Deferred taxes	(40)	86
Contractholder receivables	1,056	1,149
Goodwill	1,009	1,015
Other intangible assets	88	101
Other assets	429	357
Total assets	31,460	31,908
Claims and claim adjustment expense reserves	16,851	17,389
Unearned premium reserves	3,638	3,662
Contractholder payables	1,056	1,149
Payables for reinsurance premiums	142	171
Other liabilities	1,308	1,180
Total liabilities	22,995	23,551
Common stock	390	390
Additional paid-in capital	6,502	6,502
Retained earnings	1,073	1,042
Accumulated other comprehensive income	500	423
Total shareholders' equity	8,465	8,357
Total liabilities and shareholders' equity	31,460	31,908
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	30	37
Equity securities, available for sale, at fair value	141	130
Short-term securities	1,530	1,523
Other investments	1	1
Total investments	1,702	1,691
Cash	2	3	2	2
Investment income accrued	2	4
Deferred taxes	50	(62)
Investment in subsidiaries	28,821	28,616
Other assets	17	198
Total assets	30,594	30,450
Debt	5,657	5,654
Other liabilities	114	10
Total liabilities	5,771	5,664
Common stock	21,843	21,500
Retained earnings	27,238	24,281
Accumulated other comprehensive income	880	810
Treasury stock, at cost	(25,138)	(21,805)
Total shareholders' equity	24,823	24,786
Total liabilities and shareholders' equity	30,594	30,450
Common stock, shares authorized	1,750.0	1,750.0
Common stock, shares issued	322.2	353.5
Common stock, shares outstanding	322.2	353.5
Treasury stock, at cost, shares	437.3	401.5
Eliminations [Member]
Consolidating Balance Sheet
Investment in subsidiaries	(28,821)	(28,616)
Total assets	(28,821)	(28,616)
Common stock	(390)	(390)
Additional paid-in capital	(18,136)	(18,136)
Retained earnings	(8,733)	(8,900)
Accumulated other comprehensive income	(1,562)	(1,190)
Total shareholders' equity	(28,821)	(28,616)
Total liabilities and shareholders' equity	$ (28,821)	$ (28,616)