FAIR VALUE OF ASSETS AND LIABILITIES - Gains and Losses Resulting from Changes in Fair Value (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Future policy benefits
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	$ 715
Unrealized gains (losses) for liabilities still held	686
Policyholders' account balances
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	124
Unrealized gains (losses) for liabilities still held	89
Realized investment gains (losses), net | Future policy benefits
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	715
Unrealized gains (losses) for liabilities still held	686
Realized investment gains (losses), net | Policyholders' account balances
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	124
Unrealized gains (losses) for liabilities still held	89
Other income (loss) | Future policy benefits
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for liabilities still held	0
Other income (loss) | Policyholders' account balances
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for liabilities still held	0
Included in other comprehensive income (loss) | Future policy benefits
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for liabilities still held	0
Included in other comprehensive income (loss) | Policyholders' account balances
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for liabilities still held	0
Net investment income | Future policy benefits
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Net investment income | Policyholders' account balances
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Fixed maturity securities | Realized investment gains (losses), net | Fixed Maturity, Available-For Sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Fixed maturity securities | Other income (loss) | Fixed Maturity, Available-For Sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Fixed maturity securities | Included in other comprehensive income (loss) | Fixed Maturity, Available-For Sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	(12)
Unrealized gains (losses) for assets still held	(12)
Fixed maturity securities | Net investment income | Fixed Maturity, Available-For Sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Other assets
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	(21)
Unrealized gains (losses) for assets still held	(6)
Other assets | Realized investment gains (losses), net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	(21)
Unrealized gains (losses) for assets still held	(6)
Other assets | Other income (loss)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Other assets | Included in other comprehensive income (loss)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Other assets | Net investment income
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Reinsurance recoverables
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	201
Unrealized gains (losses) for assets still held	222
Reinsurance recoverables | Realized investment gains (losses), net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	201
Unrealized gains (losses) for assets still held	222
Reinsurance recoverables | Other income (loss)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Reinsurance recoverables | Included in other comprehensive income (loss)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	0
Unrealized gains (losses) for assets still held	0
Reinsurance recoverables | Net investment income
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total realized and unrealized gains (losses)	$ 0