Income Tax (Reconciliation of Income Tax Provision between US Statutory Rate and As Reported for Continuing Operations) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income tax expense benefit continuing operations income tax reconciliation
Tax provision at U.S. statutory rate		$ 601	$ 1,706	$ 1,455
Dividend received deduction		(20)	(40)	(34)
Tax-exempt income		15	(36)	(45)
Prior year tax (1), (2)		(15)	(127)	(27)
Low income housing tax credits		(143)	(178)	(202)
Other tax credits		(44)	(46)	(45)
Foreign tax rate differential (3), (4), (5)		(110)	267	414
Change in valuation allowance		0	1	(5)
Other, net		(17)	(4)	2
Deferred Federal Income Tax Expense (Benefit)		536	837	(115)
Provision for income tax expense (benefit)		301	1,551	1,509
MetLife Seguros de Retiro [Member]
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)				60
MetLife Russia [Member]
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)				24
MetLife Poland and Greece
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)			50
MetLife Seguros S.A
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)			41
Settlement with Taxing Authority
Income tax expense benefit continuing operations income tax reconciliation
Prior year tax (1), (2)		(32)	(117)	(40)
Provision for income tax expense (benefit)	$ (53)
GILTI [Member]
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)		12	30	$ 43
GILTI [Member] | Tax Year 2020
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)			(12)
GILTI [Member] | Tax Year 2021
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)		(21)	$ 42
GILTI [Member] | Tax Year 2022
Income tax expense benefit continuing operations income tax reconciliation
Foreign tax rate differential (3), (4), (5)		$ 33