AVAILABLE-FOR-SALE DEBT SECURITIES AND EQUITY SECURITIES - Summary of Available-for-Sale Debt Securities In Continuous Unrealized Loss Position (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Gross Unrealized Losses
Less Than 12 Months	$ (2)	$ (22)
12 Months or Longer	(8)	(12)
Total	(10)	(34)
Estimated Fair Value
Less Than 12 Months	727	1,204
12 Months or Longer	624	705
Total	1,351	1,908
U.S. treasury securities
Gross Unrealized Losses
Less Than 12 Months	0	(2)
12 Months or Longer	(1)	(3)
Total	(1)	(5)
Estimated Fair Value
Less Than 12 Months	161	174
12 Months or Longer	48	206
Total	209	379
U.S. government agencies securities
Gross Unrealized Losses
Less Than 12 Months	0	0
12 Months or Longer	0	0
Total	0	0
Estimated Fair Value
Less Than 12 Months	106	21
12 Months or Longer	2	0
Total	108	21
Non-U.S. government securities
Gross Unrealized Losses
Less Than 12 Months	0	0
12 Months or Longer	0	0
Total	0	0
Estimated Fair Value
Less Than 12 Months	5	31
12 Months or Longer	5	3
Total	10	34
Corporate debt securities
Gross Unrealized Losses
Less Than 12 Months	(1)	(17)
12 Months or Longer	(7)	(8)
Total	(8)	(26)
Estimated Fair Value
Less Than 12 Months	333	774
12 Months or Longer	546	439
Total	878	1,213
Residential mortgage and asset-backed securities
Gross Unrealized Losses
Less Than 12 Months	0	(2)
12 Months or Longer	0	(1)
Total	0	(3)
Estimated Fair Value
Less Than 12 Months	123	205
12 Months or Longer	24	56
Total	$ 147	$ 261