Pending Disposition of MetLife Poland and Greece - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended		9 Months Ended
	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)		$ 1,589	$ 709	$ 3,775	$ 4,551	$ 5,364	$ 5,260
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		2,042	923			6,820	6,763
MetLife Poland and Greece
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Agreed upon proceeds from divestiture of business.	$ 738
Dividends Receivable	$ 43
Net income (loss)						(202)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		$ 12	$ (5)			$ 40	$ 29