INSURANCE LIABILITIES AND ANNUITY BENEFITS - Changes in Future Policy Benefit Reserves (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Present value of expected future policy benefits
Net future policy benefit reserves	$ 35,599		$ 34,476
Long-term care
Present value of expected net premiums
Balance, beginning of year	4,144	$ 4,063
Beginning balance at locked-in discount rate	3,991	3,745
Effect of changes in cash flow assumptions			257	$ 387
Effect of actual variances from expected experience			(3)	(26)
Adjusted beginning of year balance			4,244	4,106
Interest accrual	164	155
Net premiums collected	(299)	(298)
Effect of foreign currency	0	0
Ending balance at locked-in discount rate	4,110	3,962
Effect of changes in discount rate assumptions	278	355
Balance, end of period	4,388	4,317
Present value of expected future policy benefits
Balance, beginning of year	28,820	30,895
Beginning balance at locked-in discount rate	27,897	27,591	27,448	27,144
Effect of changes in cash flow assumptions			308	389
Effect of actual variances from expected experience			142	24
Adjusted beginning of year balance			27,898	27,557
Interest accrual	1,129	1,112
Benefit payments	(1,130)	(1,079)
Effect of foreign currency	0	0
Ending balance at locked-in discount rate	27,897	27,591
Effect of changes in discount rate assumptions	2,291	3,540
Balance, end of period	30,188	31,131
Net future policy benefit reserves	25,801	26,813	24,675
Less: Reinsurance recoverables, net of allowance for credit losses	(157)	(185)
Net future policy benefit reserves, after reinsurance recoverables	$ 25,644	$ 26,628
Weighted-average duration of liability (years)	11 years 3 months 18 days	12 years 3 months 18 days
Weighted-average interest accretion rate	5.60%	5.60%
Current discount rate	5.30%	5.00%
Gross premiums or assessments recognized during period	$ 343	$ 359
Expected future gross premiums, undiscounted	7,499	7,517
Expected future gross premiums, discounted	4,813	4,938
Expected future benefit payments, undiscounted	61,497	62,798
Expected future benefit payments, discounted	30,188	31,131
Structured settlement annuities
Present value of expected net premiums
Balance, beginning of year	0	0
Beginning balance at locked-in discount rate	0	0
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			0	0
Adjusted beginning of year balance			0	0
Interest accrual	0	0
Net premiums collected	0	0
Effect of foreign currency	0	0
Ending balance at locked-in discount rate	0	0
Effect of changes in discount rate assumptions	0	0
Balance, end of period	0	0
Present value of expected future policy benefits
Balance, beginning of year	8,426	9,357
Beginning balance at locked-in discount rate	8,107	8,374	8,301	8,561
Effect of changes in cash flow assumptions			(37)	0
Effect of actual variances from expected experience			6	(25)
Adjusted beginning of year balance			8,270	8,536
Interest accrual	323	332
Benefit payments	(486)	(493)
Effect of foreign currency	0	0
Ending balance at locked-in discount rate	8,107	8,374
Effect of changes in discount rate assumptions	360	719
Balance, end of period	8,467	9,093
Net future policy benefit reserves	8,467	9,093	8,426
Less: Reinsurance recoverables, net of allowance for credit losses	0	0
Net future policy benefit reserves, after reinsurance recoverables	$ 8,467	$ 9,093
Weighted-average duration of liability (years)	10 years 2 months 12 days	10 years 10 months 24 days
Weighted-average interest accretion rate	5.40%	5.40%
Current discount rate	5.30%	4.90%
Gross premiums or assessments recognized during period	$ 0	$ 0
Expected future gross premiums, undiscounted	0	0
Expected future gross premiums, discounted	0	0
Expected future benefit payments, undiscounted	17,961	18,769
Expected future benefit payments, discounted	8,467	9,093
Life
Present value of expected net premiums
Balance, beginning of year	4,318	4,803
Beginning balance at locked-in discount rate	4,415	4,773
Effect of changes in cash flow assumptions			4	(1)
Effect of actual variances from expected experience			(2,343)	(5)
Adjusted beginning of year balance			2,076	4,768
Interest accrual	138	134
Net premiums collected	(223)	(212)
Effect of foreign currency	108	(41)
Ending balance at locked-in discount rate	2,099	4,649
Effect of changes in discount rate assumptions	87	(24)
Balance, end of period	2,186	4,625
Present value of expected future policy benefits
Balance, beginning of year	5,336	5,921
Beginning balance at locked-in discount rate	3,035	5,658	5,411	5,847
Effect of changes in cash flow assumptions			43	24
Effect of actual variances from expected experience			(2,381)	(4)
Adjusted beginning of year balance			3,074	$ 5,867
Interest accrual	167	164
Benefit payments	(319)	(329)
Effect of foreign currency	113	(44)
Ending balance at locked-in discount rate	3,035	5,658
Effect of changes in discount rate assumptions	127	26
Balance, end of period	3,161	5,684
Net future policy benefit reserves	976	1,060	$ 1,018
Less: Reinsurance recoverables, net of allowance for credit losses	(179)	(32)
Net future policy benefit reserves, after reinsurance recoverables	$ 797	$ 1,028
Weighted-average duration of liability (years)	6 years	5 years 7 months 6 days
Weighted-average interest accretion rate	5.30%	5.10%
Current discount rate	4.90%	4.60%
Gross premiums or assessments recognized during period	$ 249	$ 241
Expected future gross premiums, undiscounted	4,468	12,011
Expected future gross premiums, discounted	2,452	5,576
Expected future benefit payments, undiscounted	5,091	10,868
Expected future benefit payments, discounted	$ 3,161	$ 5,684