Consolidating Financial Statements (Details) - Consolidating Balance Sheet (Unaudited) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 68,011	$ 63,464
Equity securities, at fair value	412	368
Real estate investments	963	904
Short-term securities	4,597	3,985
Other investments	3,437	3,557
Total investments	77,420	72,278
Cash	508	373
Investment income accrued	575	624
Premiums receivable	8,122	7,506
Reinsurance recoverables	8,162	8,370
Ceded unearned premiums	857	578
Deferred acquisition costs	2,321	2,120
Deferred taxes	0	445
Contractholder receivables	4,802	4,785
Goodwill	3,929	3,937
Other intangible assets	329	345
Investment in subsidiaries	0	0
Other assets	3,216	2,872
Total assets	110,241	104,233
Claims and claim adjustment expense reserves	51,612	50,668
Unearned premium reserves	14,912	13,555
Contractholder payables	4,802	4,785
Payables for reinsurance premiums	573	289
Deferred taxes	188	0
Debt	6,558	6,564
Other liabilities	5,989	5,478
Total liabilities	84,634	81,339
Common stock	23,432	23,144
Additional paid-in capital	0	0
Retained earnings	36,317	35,204
Accumulated other comprehensive income (loss)	625	(1,859)
Treasury stock, at cost	(34,767)	(33,595)
Total shareholders’ equity	25,607	22,894	$ 22,460
Total liabilities and shareholders’ equity	110,241	104,233
Fixed maturities, available for sale, amortized cost	65,021	63,601
Equity securities, cost	$ 375	$ 382
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	258,100,000	263,700,000
Common stock, shares outstanding (in shares)	258,100,000	263,600,000
Treasury stock, at cost (in shares)	519,300,000	510,900,000
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 46,887	$ 43,683
Equity securities, at fair value	103	105
Real estate investments	1	2
Short-term securities	2,485	1,855
Other investments	2,682	2,746
Total investments	52,158	48,391
Cash	220	181
Investment income accrued	397	434
Premiums receivable	5,491	5,089
Reinsurance recoverables	6,416	5,904
Ceded unearned premiums	746	522
Deferred acquisition costs	2,133	1,930
Deferred taxes		167
Contractholder receivables	4,792	3,867
Goodwill	2,580	2,578
Other intangible assets	219	224
Investment in subsidiaries	0	0
Other assets	2,332	2,220
Total assets	77,484	71,507
Claims and claim adjustment expense reserves	35,445	34,093
Unearned premium reserves	10,412	9,414
Contractholder payables	4,792	3,867
Payables for reinsurance premiums	342	169
Deferred taxes	306
Debt	693	693
Other liabilities	4,497	4,133
Total liabilities	56,487	52,369
Common stock	0	0
Additional paid-in capital	11,634	11,634
Retained earnings	8,185	8,065
Accumulated other comprehensive income (loss)	1,178	(561)
Treasury stock, at cost	0	0
Total shareholders’ equity	20,997	19,138
Total liabilities and shareholders’ equity	77,484	71,507
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	21,033	19,697
Equity securities, at fair value	114	92
Real estate investments	962	902
Short-term securities	653	759
Other investments	754	810
Total investments	23,516	22,260
Cash	288	192
Investment income accrued	176	187
Premiums receivable	2,631	2,417
Reinsurance recoverables	1,746	2,466
Ceded unearned premiums	111	56
Deferred acquisition costs	188	190
Deferred taxes		302
Contractholder receivables	10	918
Goodwill	1,358	1,368
Other intangible assets	110	121
Investment in subsidiaries	0	0
Other assets	252	15
Total assets	30,386	30,492
Claims and claim adjustment expense reserves	16,167	16,575
Unearned premium reserves	4,500	4,141
Contractholder payables	10	918
Payables for reinsurance premiums	231	120
Deferred taxes	(147)
Debt	0	32
Other liabilities	956	849
Total liabilities	21,717	22,635
Common stock	584	401
Additional paid-in capital	7,046	7,023
Retained earnings	776	879
Accumulated other comprehensive income (loss)	263	(446)
Treasury stock, at cost	0	0
Total shareholders’ equity	8,669	7,857
Total liabilities and shareholders’ equity	30,386	30,492
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	91	84
Equity securities, at fair value	195	171
Real estate investments	0	0
Short-term securities	1,459	1,371
Other investments	1	1
Total investments	1,746	1,627
Cash	0	0
Investment income accrued	2	3
Premiums receivable	0	0
Reinsurance recoverables	0	0
Ceded unearned premiums	0	0
Deferred acquisition costs	0	0
Deferred taxes		(24)
Contractholder receivables	0	0
Goodwill	0	0
Other intangible assets	0	0
Investment in subsidiaries	29,665	26,993
Other assets	632	669
Total assets	32,045	29,268
Claims and claim adjustment expense reserves	0	0
Unearned premium reserves	0	0
Contractholder payables	0	0
Payables for reinsurance premiums	0	0
Deferred taxes	29
Debt	5,865	5,871
Other liabilities	536	496
Total liabilities	6,430	6,367
Common stock	23,432	23,144
Additional paid-in capital	0	0
Retained earnings	36,325	35,211
Accumulated other comprehensive income (loss)	625	(1,859)
Treasury stock, at cost	(34,767)	(33,595)
Total shareholders’ equity	25,615	22,901
Total liabilities and shareholders’ equity	32,045	29,268
Eliminations [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	0	0
Equity securities, at fair value	0	0
Real estate investments	0	0
Short-term securities	0	0
Other investments	0	0
Total investments	0	0
Cash	0	0
Investment income accrued	0	0
Premiums receivable	0	0
Reinsurance recoverables	0	0
Ceded unearned premiums	0	0
Deferred acquisition costs	0	0
Deferred taxes		0
Contractholder receivables	0	0
Goodwill	(9)	(9)
Other intangible assets	0	0
Investment in subsidiaries	(29,665)	(26,993)
Other assets	0	(32)
Total assets	(29,674)	(27,034)
Claims and claim adjustment expense reserves	0	0
Unearned premium reserves	0	0
Contractholder payables	0	0
Payables for reinsurance premiums	0	0
Deferred taxes	0
Debt	0	(32)
Other liabilities	0	0
Total liabilities	0	(32)
Common stock	(584)	(401)
Additional paid-in capital	(18,680)	(18,657)
Retained earnings	(8,969)	(8,951)
Accumulated other comprehensive income (loss)	(1,441)	1,007
Treasury stock, at cost	0	0
Total shareholders’ equity	(29,674)	(27,002)
Total liabilities and shareholders’ equity	$ (29,674)	$ (27,034)