INVESTMENTS - Available-for-sale Securities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 61,707		$ 61,707		$ 61,884
Allowance for Credit Losses	4		4		4
Gross Unrealized Gains	194		194		257
Gross Unrealized Losses	7,962		7,962		6,972
Fair Value	53,935		53,935		55,165
Amortized Cost (Less Allowance for Credit Losses)
Due in one year or less	1,720		1,720
Due in years two through five	12,032		12,032
Due in years six through ten	12,449		12,449
Due after ten years	22,770		22,770
Subtotal	48,971		48,971
Amortized Cost (Less Allowance for Credit Losses)	61,703		61,703
Fair Value
Due in one year or less	1,699		1,699
Due in years two through five	11,534		11,534
Due in years six through ten	11,344		11,344
Due after ten years	17,227		17,227
Subtotal	41,804		41,804
Fair Value	53,935		53,935		55,165
Available For Sale Fixed Maturities Proceeds Gross Gains And Gross Losses From Sales And Other Than Temporary Impairments [Abstract]
Proceeds from sales	309	$ 2,233	753	$ 2,961
Gross gains on sales	2	5	2	7
Gross losses on sales	(3)	(46)	(27)	(64)
Net (increase) decrease in Allowance for Credit and Intent to Sell losses	(3)	(7)	(5)	(62)
Fixed Maturities - Credit Loss Impairments
Balances, beginning of period	48	87	48	36
Previously recognized impairments on securities that matured, paid, prepaid or sold	(4)	(52)	(8)	(55)
Recognized impairments on securities impaired to fair value this period	0	0	0	50
Credit losses recognized this period on securities for which credit losses were not previously recognized	3	6	6	9
Additional credit losses this period on securities previously impaired	3	3	4	4
Balances, end of period	50	$ 44	50	$ 44
Corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	42,209		42,209		42,014
Allowance for Credit Losses	4		4		4
Gross Unrealized Gains	157		157		217
Gross Unrealized Losses	5,774		5,774		4,960
Fair Value	36,588		36,588		37,267
Fair Value
Fair Value	36,588		36,588		37,267
U.S. Treasury, government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	5,677		5,677		5,639
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	0		0		2
Gross Unrealized Losses	1,356		1,356		1,102
Fair Value	4,321		4,321		4,539
Fair Value
Fair Value	4,321		4,321		4,539
States and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	432		432		525
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	2		2		9
Gross Unrealized Losses	71		71		64
Fair Value	363		363		470
Fair Value
Fair Value	363		363		470
Foreign governments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	657		657		689
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	1		1		2
Gross Unrealized Losses	126		126		110
Fair Value	532		532		581
Fair Value
Fair Value	532		532		581
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,642		1,642		1,469
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	2		2		3
Gross Unrealized Losses	138		138		128
Fair Value	1,506		1,506		1,344
Amortized Cost (Less Allowance for Credit Losses)
Without single maturity date	1,642		1,642
Fair Value
Without single maturity date	1,506		1,506
Fair Value	1,506		1,506		1,344
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,645		7,645		8,092
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	29		29		20
Gross Unrealized Losses	72		72		107
Fair Value	7,602		7,602		8,005
Amortized Cost (Less Allowance for Credit Losses)
Without single maturity date	7,645		7,645
Fair Value
Without single maturity date	7,602		7,602
Fair Value	7,602		7,602		8,005
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,389		3,389		3,400
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	1		1		1
Gross Unrealized Losses	425		425		501
Fair Value	2,965		2,965		2,900
Amortized Cost (Less Allowance for Credit Losses)
Without single maturity date	3,389		3,389
Fair Value
Without single maturity date	2,965		2,965
Fair Value	2,965		2,965		2,900
Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	56		56		56
Allowance for Credit Losses	0		0		0
Gross Unrealized Gains	2		2		3
Gross Unrealized Losses	0		0		0
Fair Value	58		58		59
Amortized Cost (Less Allowance for Credit Losses)
Without single maturity date	56		56
Fair Value
Without single maturity date	58		58
Fair Value	$ 58		$ 58		$ 59