Consolidating Financial Statements (Details) - Consolidating Balance Sheet (Unaudited) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 67,172	$ 63,464
Equity securities, at fair value	406	368
Real estate investments	965	904
Short-term securities	3,487	3,985
Other investments	3,466	3,557
Total investments	75,496	72,278
Cash	416	373	$ 415	$ 344
Investment income accrued	615	624
Premiums receivable	8,297	7,506
Reinsurance recoverables	8,234	8,370
Ceded unearned premiums	864	578
Deferred acquisition costs	2,281	2,120
Deferred taxes	0	445
Contractholder receivables	4,776	4,785
Goodwill	3,943	3,937
Other intangible assets	335	345
Investment in subsidiaries	0	0
Other assets	3,315	2,872
Total assets	108,572	104,233
Claims and claim adjustment expense reserves	51,073	50,668
Unearned premium reserves	14,538	13,555
Contractholder payables	4,776	4,785
Payables for reinsurance premiums	591	289
Deferred taxes	87	0
Debt	6,558	6,564
Other liabilities	5,628	5,478
Total liabilities	83,251	81,339
Common stock	23,372	23,144
Additional paid-in capital	0	0
Retained earnings	36,135	35,204
Accumulated other comprehensive income (loss)	206	(1,859)
Treasury stock, at cost	(34,392)	(33,595)
Total shareholders’ equity	25,321	22,894	22,623
Total liabilities and shareholders’ equity	108,572	104,233
Fixed maturities, available for sale, amortized cost	64,784	63,601
Equity securities, cost	$ 373	$ 382
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	260,400,000	263,700,000
Common stock, shares outstanding (in shares)	260,300,000	263,600,000
Treasury stock, at cost (in shares)	516,700,000	510,900,000
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 46,480	$ 43,683
Equity securities, at fair value	105	105
Real estate investments	2	2
Short-term securities	1,439	1,855
Other investments	2,688	2,746
Total investments	50,714	48,391
Cash	198	181	231	157
Investment income accrued	430	434
Premiums receivable	5,587	5,089
Reinsurance recoverables	6,472	5,904
Ceded unearned premiums	742	522
Deferred acquisition costs	2,087	1,930
Deferred taxes		167
Contractholder receivables	4,766	3,867
Goodwill	2,582	2,578
Other intangible assets	220	224
Investment in subsidiaries	0	0
Other assets	2,472	2,220
Total assets	76,270	71,507
Claims and claim adjustment expense reserves	35,055	34,093
Unearned premium reserves	10,116	9,414
Contractholder payables	4,766	3,867
Payables for reinsurance premiums	340	169
Deferred taxes	234
Debt	693	693
Other liabilities	4,224	4,133
Total liabilities	55,428	52,369
Common stock	0	0
Additional paid-in capital	11,634	11,634
Retained earnings	8,336	8,065
Accumulated other comprehensive income (loss)	872	(561)
Treasury stock, at cost	0	0
Total shareholders’ equity	20,842	19,138
Total liabilities and shareholders’ equity	76,270	71,507
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	20,604	19,697
Equity securities, at fair value	106	92
Real estate investments	963	902
Short-term securities	633	759
Other investments	777	810
Total investments	23,083	22,260
Cash	218	192	184	187
Investment income accrued	183	187
Premiums receivable	2,710	2,417
Reinsurance recoverables	1,762	2,466
Ceded unearned premiums	122	56
Deferred acquisition costs	194	190
Deferred taxes		302
Contractholder receivables	10	918
Goodwill	1,370	1,368
Other intangible assets	115	121
Investment in subsidiaries	0	0
Other assets	158	15
Total assets	29,925	30,492
Claims and claim adjustment expense reserves	16,018	16,575
Unearned premium reserves	4,422	4,141
Contractholder payables	10	918
Payables for reinsurance premiums	251	120
Deferred taxes	(179)
Debt	0	32
Other liabilities	902	849
Total liabilities	21,424	22,635
Common stock	484	401
Additional paid-in capital	7,046	7,023
Retained earnings	808	879
Accumulated other comprehensive income (loss)	163	(446)
Treasury stock, at cost	0	0
Total shareholders’ equity	8,501	7,857
Total liabilities and shareholders’ equity	29,925	30,492
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	88	84
Equity securities, at fair value	195	171
Real estate investments	0	0
Short-term securities	1,415	1,371
Other investments	1	1
Total investments	1,699	1,627
Cash	0	0	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	29,342	26,993
Other assets	685	669
Total assets	31,728	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	32
Debt	5,865	5,871
Other liabilities	502	496
Total liabilities	6,399	6,367
Common stock	23,372	23,144
Additional paid-in capital	0	0
Retained earnings	36,143	35,211
Accumulated other comprehensive income (loss)	206	(1,859)
Treasury stock, at cost	(34,392)	(33,595)
Total shareholders’ equity	25,329	22,901
Total liabilities and shareholders’ equity	31,728	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	$ 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	(29,342)	(26,993)
Other assets	0	(32)
Total assets	(29,351)	(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	(484)	(401)
Additional paid-in capital	(18,680)	(18,657)
Retained earnings	(9,152)	(8,951)
Accumulated other comprehensive income (loss)	(1,035)	1,007
Treasury stock, at cost	0	0
Total shareholders’ equity	(29,351)	(27,002)
Total liabilities and shareholders’ equity	$ (29,351)	$ (27,034)