Consolidating Financial Statements (details) - Consolidating Balance Sheet (Unaudited) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	$ 61,671	$ 63,474
Equity securities, available for sale, at fair value	719	899
Real estate investments	1,011	938
Short-term securities	5,128	4,364
Other investments	3,530	3,586
Total investments	72,059	73,261
Cash	344	374	$ 367	$ 294
Investment income accrued	613	685
Premiums receivable	6,559	6,298
Reinsurance recoverables	8,949	9,260
Ceded unearned premiums	789	678
Deferred acquisition costs	1,904	1,835
Deferred taxes	241	33
Contractholder receivables	4,390	4,362
Goodwill	3,579	3,611
Other intangible assets	280	304
Other assets	2,403	2,377
Total assets	102,110	103,078
Claims and claim adjustment expense reserves	48,596	49,850
Unearned premium reserves	12,284	11,839
Contractholder payables	4,390	4,362
Payables for reinsurance premiums	439	336
Debt	6,743	6,349
Other liabilities	5,625	5,506
Total liabilities	78,077	78,242
Common stock	22,099	21,843	21,764	21,500
Retained earnings	29,263	27,251	26,394	24,291
Accumulated other comprehensive income	32	880	1,300	810
Treasury stock, at cost	(27,361)	(25,138)	(24,137)	$ (21,805)
Total shareholders' equity	24,033	24,836	$ 25,321
Total liabilities and shareholders' equity	102,110	103,078
Fixed maturities, available for sale, amortized cost	59,688	60,801
Equity securities, available for sale, cost	$ 553	$ 579
Common stock, shares authorized	1,750.0	1,750.0
Common stock, shares issued	304.2	322.2
Common stock, shares outstanding	304.2	322.2	331.4	353.5
Treasury stock, at cost, shares	458.8	437.3
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	$ 42,426	$ 43,401
Equity securities, available for sale, at fair value	200	236
Real estate investments	56	56
Short-term securities	2,295	2,128
Other investments	2,578	2,630
Total investments	47,555	48,451
Cash	201	221	$ 216	$ 137
Investment income accrued	423	468
Premiums receivable	4,433	4,241
Reinsurance recoverables	5,846	6,156
Ceded unearned premiums	713	608
Deferred acquisition costs	1,702	1,622
Deferred taxes	127	23
Contractholder receivables	3,370	3,306
Goodwill	2,577	2,602
Other intangible assets	201	216
Other assets	2,003	1,931
Total assets	69,151	69,845
Claims and claim adjustment expense reserves	32,124	32,999
Unearned premium reserves	8,576	8,201
Contractholder payables	3,370	3,306
Payables for reinsurance premiums	264	194
Debt	692	692
Other liabilities	4,142	4,084
Total liabilities	49,168	49,476
Additional paid-in capital	11,634	11,634
Retained earnings	7,857	7,673
Accumulated other comprehensive income	492	1,062
Total shareholders' equity	19,983	20,369
Total liabilities and shareholders' equity	69,151	69,845
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	19,199	20,043
Equity securities, available for sale, at fair value	383	522
Real estate investments	955	882
Short-term securities	877	706
Other investments	951	955
Total investments	22,365	23,108
Cash	141	151	149	154
Investment income accrued	186	215
Premiums receivable	2,126	2,057
Reinsurance recoverables	3,103	3,104
Ceded unearned premiums	76	70
Deferred acquisition costs	202	213
Deferred taxes	56	(40)
Contractholder receivables	1,020	1,056
Goodwill	1,002	1,009
Other intangible assets	79	88
Other assets	385	429
Total assets	30,741	31,460
Claims and claim adjustment expense reserves	16,472	16,851
Unearned premium reserves	3,708	3,638
Contractholder payables	1,020	1,056
Payables for reinsurance premiums	175	142
Other liabilities	1,222	1,308
Total liabilities	22,597	22,995
Common stock	390	390
Additional paid-in capital	6,502	6,502
Retained earnings	1,070	1,073
Accumulated other comprehensive income	182	500
Total shareholders' equity	8,144	8,465
Total liabilities and shareholders' equity	30,741	31,460
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	46	30
Equity securities, available for sale, at fair value	136	141
Short-term securities	1,956	1,530
Other investments	1	1
Total investments	2,139	1,702
Cash	2	2	$ 2	$ 3
Investment income accrued	4	2
Deferred taxes	58	50
Investment in subsidiaries	28,115	28,821
Other assets	15	17
Total assets	30,333	30,594
Debt	6,051	5,657
Other liabilities	261	114
Total liabilities	6,312	5,771
Common stock	22,099	21,843
Retained earnings	29,251	27,238
Accumulated other comprehensive income	32	880
Treasury stock, at cost	(27,361)	(25,138)
Total shareholders' equity	24,021	24,823
Total liabilities and shareholders' equity	30,333	30,594
Eliminations [Member]
Consolidating Balance Sheet
Investment in subsidiaries	(28,115)	(28,821)
Total assets	(28,115)	(28,821)
Common stock	(390)	(390)
Additional paid-in capital	(18,136)	(18,136)
Retained earnings	(8,915)	(8,733)
Accumulated other comprehensive income	(674)	(1,562)
Total shareholders' equity	(28,115)	(28,821)
Total liabilities and shareholders' equity	$ (28,115)	$ (28,821)