Pending Disposition of MetLife Poland and Greece - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended				6 Months Ended
	Jul. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)		$ 3,412	$ 363	$ 150	$ 4,401	$ 3,775	$ 4,551
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		4,487		197		4,778	5,840
MetLife Poland and Greece
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)		190				190
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		$ 13		$ 15		$ 28	$ 34
Subsequent Event [Member] | 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