Insurance (Insurance Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	$ 426,961	$ 420,945
U.S.
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	171,693	162,999
Asia
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	125,523	125,839
Latin America
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	17,674	15,564
EMEA
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	10,635	13,031
MetLife Holdings
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	100,407	102,291
Corporate & Other
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	$ 1,029	$ 1,221