SIGNIFICANT ACCOUNTING POLICIES - Schedule of Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2020
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	$ 4,771	$ 4,814	$ 4,098
Closed block liabilities	5,618	5,760
Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			3,771
Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			327
Closed block liabilities			136
Protection Solutions | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			3
Term | Protection Solutions
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	344	362	403
Term | Protection Solutions | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			403
Term | Protection Solutions | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
UL | Protection Solutions
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	22	20	5
UL | Protection Solutions | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
UL | Protection Solutions | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			5
VUL | Protection Solutions
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	160	112	6
VUL | Protection Solutions | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
VUL | Protection Solutions | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			6
IUL | Protection Solutions
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
IUL | Protection Solutions | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
IUL | Protection Solutions | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			0
GMxB Legacy | Legacy Segment
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	210	213	200
GMxB Legacy | Legacy Segment | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			192
GMxB Legacy | Legacy Segment | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			8
GMxB Core | Individual Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	1,509	1,585	1,646
GMxB Core | Individual Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			1,635
GMxB Core | Individual Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			11
EI | Individual Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	151	156	154
EI | Individual Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			141
EI | Individual Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			13
IE | Individual Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	150	147	94
IE | Individual Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			95
IE | Individual Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			(1)
SCS | Individual Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			855
SCS | Individual Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			645
SCS | Individual Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			210
EG | Group Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	718	711	634
EG | Group Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			581
EG | Group Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			53
Momentum | Group Retirement
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC	$ 83	$ 89	101
Momentum | Group Retirement | Previously Reported
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			79
Momentum | Group Retirement | Adjustment for reversal of balances recorded in Accumulated Other Comprehensive Income
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
DAC			$ 22