Consolidating Financial Statements (details) - Consolidating Balance Sheet (Unaudited) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	$ 62,102	$ 65,393
Equity securities, available for sale, at fair value	708	645
Real estate investments	917	883
Short-term securities	5,379	3,483
Other investments	3,425	3,434
Total investments	72,531	73,838
Cash	295	330	220	214
Investment income accrued	673	752
Premiums receivable	6,113	5,872
Reinsurance recoverables	9,544	10,712
Ceded unearned premiums	1,015	856
Deferred acquisition costs	1,802	1,792
Deferred taxes	321
Contractholder receivables	4,450	4,806
Goodwill	3,365	3,365
Other intangible assets	347	381
Other assets	2,229	2,234
Total assets	102,685	104,938
Claims and claim adjustment expense reserves	49,153	50,922
Unearned premium reserves	11,716	11,241
Contractholder payables	4,450	4,806
Payables for reinsurance premiums	438	346
Deferred taxes		338
Debt	6,346	6,350
Other liabilities	5,771	5,530
Total liabilities	77,874	79,533
Common stock	21,425	21,161	21,085	20,732
Retained earnings	23,485	21,352	21,226	19,579
Accumulated other comprehensive income	705	2,236	2,536	2,005
Treasury stock, at cost	(20,804)	(19,344)	(18,942)	(17,839)
Total shareholders' equity	24,811	25,405	25,905
Total liabilities and shareholders' equity	102,685	104,938
Fixed maturities, available for sale, amortized cost	59,960	60,829
Equity securities, available for sale, cost	470	462
Common stock, shares authorized	1,750.0	1,750.0
Common stock, shares issued	364.1	377.4
Common stock, shares outstanding	364.1	377.4	382.0	392.8
Treasury stock, at cost, shares	390.1	372.3
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	42,493	44,336
Equity securities, available for sale, at fair value	159	153
Real estate investments	32	33
Short-term securities	2,750	1,187
Other investments	2,437	2,443
Total investments	47,871	48,152
Cash	130	177	118	114
Investment income accrued	457	507
Premiums receivable	4,107	3,944
Reinsurance recoverables	6,153	7,112
Ceded unearned premiums	858	698
Deferred acquisition costs	1,578	1,560
Deferred taxes	159
Contractholder receivables	3,253	3,540
Goodwill	2,411	2,411
Other intangible assets	245	268
Other assets	1,882	1,930
Total assets	69,104	70,299
Claims and claim adjustment expense reserves	32,232	33,598
Unearned premium reserves	8,136	7,751
Contractholder payables	3,253	3,540
Payables for reinsurance premiums	219	151
Deferred taxes		316
Debt	692	1,191
Other liabilities	4,106	4,107
Total liabilities	48,638	50,654
Additional paid-in capital	11,635	11,135
Retained earnings	7,873	6,404
Accumulated other comprehensive income	958	2,106
Total shareholders' equity	20,466	19,645
Total liabilities and shareholders' equity	69,104	70,299
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	19,572	21,019
Equity securities, available for sale, at fair value	428	386
Real estate investments	885	850
Short-term securities	833	338
Other investments	987	990
Total investments	22,705	23,583
Cash	163	151	101	98
Investment income accrued	210	240
Premiums receivable	2,006	1,928
Reinsurance recoverables	3,391	3,600
Ceded unearned premiums	157	158
Deferred acquisition costs	224	232
Deferred taxes	55
Contractholder receivables	1,197	1,266
Goodwill	954	954
Other intangible assets	102	113
Other assets	327	286
Total assets	31,491	32,511
Claims and claim adjustment expense reserves	16,921	17,324
Unearned premium reserves	3,580	3,490
Contractholder payables	1,197	1,266
Payables for reinsurance premiums	219	195
Deferred taxes		123
Other liabilities	1,195	1,186
Total liabilities	23,112	23,584
Common stock	390	390
Additional paid-in capital	6,501	6,501
Retained earnings	1,003	1,113
Accumulated other comprehensive income	485	923
Total shareholders' equity	8,379	8,927
Total liabilities and shareholders' equity	31,491	32,511
Reportable Legal Entities [Member] | Travelers [Member]
Consolidating Balance Sheet
Fixed maturities, available for sale, at fair value	37	38
Equity securities, available for sale, at fair value	121	106
Short-term securities	1,796	1,958
Other investments	1	1
Total investments	1,955	2,103
Cash	2	2	1	2
Investment income accrued	6	5
Deferred taxes	107
Investment in subsidiaries	28,835	28,562
Other assets	20	18
Total assets	30,925	30,690
Deferred taxes		(101)
Debt	5,654	5,159
Other liabilities	470	237
Total liabilities	6,124	5,295
Common stock	21,425	21,161
Retained earnings	23,475	21,342
Accumulated other comprehensive income	705	2,236
Treasury stock, at cost	(20,804)	(19,344)
Total shareholders' equity	24,801	25,395
Total liabilities and shareholders' equity	30,925	30,690
Eliminations [Member]
Consolidating Balance Sheet
Investment in subsidiaries	(28,835)	(28,562)
Total assets	(28,835)	(28,562)
Common stock	(390)	(390)
Additional paid-in capital	(18,136)	(17,636)
Retained earnings	(8,866)	(7,507)
Accumulated other comprehensive income	(1,443)	(3,029)
Total shareholders' equity	(28,835)	(28,562)
Total liabilities and shareholders' equity	$ (28,835)	$ (28,562)