LIABILITIES FOR FUTURE POLICYHOLDER BENEFITS - Policyholder Account Balance And Liability For Unpaid Claims And Claims Adjustment Expense (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	$ 17,372	$ 17,613	$ 17,433	$ 17,340	$ 17,374
Future policyholder benefits total
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	15,195	15,508
Subtotal
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	9,145	9,403
Term
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	1,292	1,285
Payout
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	4,782	5,050
Group Pension - Benefit Reserve & DPL
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	454	460
Health
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	1,353	1,362
UL
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	1,264	1,246
Whole Life Closed Block and Open Block products
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	5,142	5,204
Other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	908	901
Other policyholder funds and dividends payable
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits and other policyholders’ liabilities	$ 2,177	$ 2,105