Dispositions - Disposition of MetLife Hong Kong (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Business	$ 6,575	$ 5,418	$ 5,909
Net investment gains (losses)	1,529	(110)	444
Goodwill, Written off Related to Sale of Business Unit			71
Provision for income tax expense (benefit)	$ 1,551	1,509	886
MetLife Hong Kong
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Business		11	(140)
Net investment gains (losses)			(100)
Goodwill, Written off Related to Sale of Business Unit			71
Provision for income tax expense (benefit)			$ 40
Total Loss on Sale of Business		$ 129