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Market Risk Benefits - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Market Risk Benefit [Line Items]
Asset	$ 286	$ 280
Liability	3,179	3,763		$ 7,901
Net	2,893	3,483
Retirement Assurance \| Asia
Market Risk Benefit [Line Items]
Asset	0	0
Liability	203	226
Net	203	226	$ 277		$ 318
Investment Product \| MetLife Holdings
Market Risk Benefit [Line Items]
Asset	156	153
Liability	2,878	3,378
Net	2,722	3,225
Insurance, Other
Market Risk Benefit [Line Items]
Asset	130	127
Liability	98	159
Net	$ (32)	$ 32	$ 491		$ 582