FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Carried at Cost or Amortized Cost (Details) - USD ($) $ in Millions	Mar. 31, 2024		Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	$ 6,677		$ 4,530
Assets:
Amortized Cost	16,694		17,824
Fixed maturity securities, held-to-maturity, fair value	18,245		19,657
Commercial mortgage and other loans	12,360		12,527
Commercial mortgage and other loans, fair value	12,017		12,217
Other investments carried at amortized cost	42	[1]	35	[2]
Other investments carried at amortized cost, fair value	42	[1]	35	[2]
Total financial instruments assets not carried at fair value	29,091		30,381
Assets fair value disclosure financial instruments carried at cost	30,304		31,909
Liabilities:
Other policyholders’ funds	5,831		6,169
Other policyholders' funds fair value disclosure	5,750		6,080
Notes payable	7,799		7,240
Notes payable, fair value disclosure	7,466		6,930
Total financial instrument liabilities not carried at fair value	13,630		13,409
Liabilities fair value disclosure financial instruments carried at cost	13,216		13,010
Government and agencies
Assets:
Amortized Cost	16,000		17,083
Fixed maturity securities, held-to-maturity, fair value	17,474		18,829
Municipalities
Assets:
Amortized Cost	248		266
Fixed maturity securities, held-to-maturity, fair value	285		307
Public utilities
Assets:
Amortized Cost	33		34
Fixed maturity securities, held-to-maturity, fair value	36		38
Sovereign and supranational
Assets:
Amortized Cost	391		418
Fixed maturity securities, held-to-maturity, fair value	431		462
Other corporate
Assets:
Amortized Cost	17		18
Fixed maturity securities, held-to-maturity, fair value	19		21
Policy loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	203		214
Equity method investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	2,838		2,750
Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	253		227
Level 1
Assets:
Fixed maturity securities, held-to-maturity, fair value	17,319		18,662
Commercial mortgage and other loans, fair value	0		0
Other investments carried at amortized cost, fair value	0	[1]	0	[2]
Assets fair value disclosure financial instruments carried at cost	17,319		18,662
Liabilities:
Other policyholders' funds fair value disclosure	0		0
Notes payable, fair value disclosure	0		0
Liabilities fair value disclosure financial instruments carried at cost	0		0
Level 1 | Government and agencies
Assets:
Fixed maturity securities, held-to-maturity, fair value	17,319		18,662
Level 1 | Municipalities
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 1 | Public utilities
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 1 | Sovereign and supranational
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 1 | Other corporate
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 2
Assets:
Fixed maturity securities, held-to-maturity, fair value	926		995
Commercial mortgage and other loans, fair value	0		0
Other investments carried at amortized cost, fair value	42	[1]	35	[2]
Assets fair value disclosure financial instruments carried at cost	968		1,030
Liabilities:
Other policyholders' funds fair value disclosure	0		0
Notes payable, fair value disclosure	6,762		6,178
Liabilities fair value disclosure financial instruments carried at cost	6,762		6,178
Level 2 | Government and agencies
Assets:
Fixed maturity securities, held-to-maturity, fair value	155		167
Level 2 | Municipalities
Assets:
Fixed maturity securities, held-to-maturity, fair value	285		307
Level 2 | Public utilities
Assets:
Fixed maturity securities, held-to-maturity, fair value	36		38
Level 2 | Sovereign and supranational
Assets:
Fixed maturity securities, held-to-maturity, fair value	431		462
Level 2 | Other corporate
Assets:
Fixed maturity securities, held-to-maturity, fair value	19		21
Level 3
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Commercial mortgage and other loans, fair value	12,017		12,217
Other investments carried at amortized cost, fair value	0	[1]	0	[2]
Assets fair value disclosure financial instruments carried at cost	12,017		12,217
Liabilities:
Other policyholders' funds fair value disclosure	5,750		6,080
Notes payable, fair value disclosure	704		752
Liabilities fair value disclosure financial instruments carried at cost	6,454		6,832
Level 3 | Government and agencies
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 3 | Municipalities
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 3 | Public utilities
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 3 | Sovereign and supranational
Assets:
Fixed maturity securities, held-to-maturity, fair value	0		0
Level 3 | Other corporate
Assets:
Fixed maturity securities, held-to-maturity, fair value	$ 0		$ 0

[1] Excludes policy loans of $203, equity method investments of $2,838, and REO of $253, at carrying value.

[2] Excludes policy loans of $214, equity method investments of $2,750, and REO of $227, at carrying value.