Consolidating Financial Statements (Details) - Consolidating Balance Sheet (Unaudited) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 68,134	$ 63,464
Equity securities, at fair value	425	368
Real estate investments	963	904
Short-term securities	4,943	3,985
Other investments	3,419	3,557
Total investments	77,884	72,278
Cash	494	373
Investment income accrued	618	624
Premiums receivable	7,909	7,506
Reinsurance recoverables	8,235	8,370
Ceded unearned premiums	689	578
Deferred acquisition costs	2,273	2,120
Deferred taxes	0	445
Contractholder receivables	4,619	4,785
Goodwill	3,961	3,937
Other intangible assets	330	345
Investment in subsidiaries	0	0
Other assets	3,110	2,872
Total assets	110,122	104,233
Claims and claim adjustment expense reserves	51,849	50,668
Unearned premium reserves	14,604	13,555
Contractholder payables	4,619	4,785
Payables for reinsurance premiums	363	289
Deferred taxes	137	0
Debt	6,558	6,564
Other liabilities	6,049	5,478
Total liabilities	84,179	81,339
Common stock	23,469	23,144
Additional paid-in capital	0	0
Retained earnings	36,977	35,204
Accumulated other comprehensive income (loss)	640	(1,859)
Treasury stock, at cost	(35,143)	(33,595)
Total shareholders’ equity	25,943	22,894	$ 23,731
Total liabilities and shareholders’ equity	110,122	104,233
Fixed maturities, available for sale, amortized cost	65,281	63,601
Equity securities, cost	$ 376	$ 382
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	255,500,000	263,700,000
Common stock, shares outstanding (in shares)	255,500,000	263,600,000
Treasury stock, at cost, shares (in shares)	522,100,000	510,900,000
TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 91	$ 84
Equity securities, at fair value	209	171
Short-term securities	1,390	1,371
Investment in subsidiaries	30,028	26,993
Total assets	32,054	29,268
Debt	5,865	5,871
Total liabilities	6,104	6,367
Common stock	23,469	23,144
Retained earnings	36,984	35,211
Accumulated other comprehensive income (loss)	640	(1,859)
Treasury stock, at cost	(35,143)	(33,595)
Total shareholders’ equity	25,950	22,901
Total liabilities and shareholders’ equity	$ 32,054	$ 29,268
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	255,500,000	263,700,000
Common stock, shares outstanding (in shares)	255,500,000	263,600,000
Treasury stock, at cost, shares (in shares)	522,100,000	510,900,000
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 46,805	$ 43,683
Equity securities, at fair value	102	105
Real estate investments	1	2
Short-term securities	2,793	1,855
Other investments	2,690	2,746
Total investments	52,391	48,391
Cash	207	181
Investment income accrued	428	434
Premiums receivable	5,331	5,089
Reinsurance recoverables	6,511	5,904
Ceded unearned premiums	603	522
Deferred acquisition costs	2,094	1,930
Deferred taxes		167
Contractholder receivables	4,606	3,867
Goodwill	2,584	2,578
Other intangible assets	218	224
Investment in subsidiaries	0	0
Other assets	2,360	2,220
Total assets	77,333	71,507
Claims and claim adjustment expense reserves	35,568	34,093
Unearned premium reserves	10,144	9,414
Contractholder payables	4,606	3,867
Payables for reinsurance premiums	210	169
Deferred taxes	272
Debt	693	693
Other liabilities	4,609	4,133
Total liabilities	56,102	52,369
Common stock	0	0
Additional paid-in capital	11,634	11,634
Retained earnings	8,451	8,065
Accumulated other comprehensive income (loss)	1,146	(561)
Treasury stock, at cost	0	0
Total shareholders’ equity	21,231	19,138
Total liabilities and shareholders’ equity	77,333	71,507
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	21,238	19,697
Equity securities, at fair value	114	92
Real estate investments	962	902
Short-term securities	760	759
Other investments	728	810
Total investments	23,802	22,260
Cash	287	192
Investment income accrued	186	187
Premiums receivable	2,578	2,417
Reinsurance recoverables	1,724	2,466
Ceded unearned premiums	86	56
Deferred acquisition costs	179	190
Deferred taxes		302
Contractholder receivables	13	918
Goodwill	1,386	1,368
Other intangible assets	112	121
Investment in subsidiaries	0	0
Other assets	419	15
Total assets	30,772	30,492
Claims and claim adjustment expense reserves	16,281	16,575
Unearned premium reserves	4,460	4,141
Contractholder payables	13	918
Payables for reinsurance premiums	153	120
Deferred taxes	(170)
Debt	0	32
Other liabilities	1,236	849
Total liabilities	21,973	22,635
Common stock	585	401
Additional paid-in capital	7,073	7,023
Retained earnings	823	879
Accumulated other comprehensive income (loss)	318	(446)
Treasury stock, at cost	0	0
Total shareholders’ equity	8,799	7,857
Total liabilities and shareholders’ equity	30,772	30,492
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	91	84
Equity securities, at fair value	209	171
Real estate investments	0	0
Short-term securities	1,390	1,371
Other investments	1	1
Total investments	1,691	1,627
Cash	0	0
Investment income accrued	4	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	30,028	26,993
Other assets	331	669
Total assets	32,054	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	35
Debt	5,865	5,871
Other liabilities	204	496
Total liabilities	6,104	6,367
Common stock	23,469	23,144
Additional paid-in capital	0	0
Retained earnings	36,984	35,211
Accumulated other comprehensive income (loss)	640	(1,859)
Treasury stock, at cost	(35,143)	(33,595)
Total shareholders’ equity	25,950	22,901
Total liabilities and shareholders’ equity	32,054	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	(30,028)	(26,993)
Other assets	0	(32)
Total assets	(30,037)	(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	(585)	(401)
Additional paid-in capital	(18,707)	(18,657)
Retained earnings	(9,281)	(8,951)
Accumulated other comprehensive income (loss)	(1,464)	1,007
Treasury stock, at cost	0	0
Total shareholders’ equity	(30,037)	(27,002)
Total liabilities and shareholders’ equity	$ (30,037)	$ (27,034)