Consolidated Supplementary Insurance Information (Balance Sheet Items) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	$ 16,061	$ 16,389	$ 17,833
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	219,154	226,726
Policyholder account balances	203,473	205,176
Policyholder Dividends Payable	478	587
Unearned Premiums	2,892	2,846
Unearned Revenue	2,368	2,112
U.S.
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	440	434
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	85,108	85,037
Policyholder account balances	77,891	77,487
Policyholder Dividends Payable	0	0
Unearned Premiums	325	175
Unearned Revenue	38	42
Asia
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	9,339	9,333
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	42,103	45,202
Policyholder account balances	83,736	81,710
Policyholder Dividends Payable	85	87
Unearned Premiums	2,386	2,493
Unearned Revenue	790	587
Latin America
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	2,021	2,092
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	10,541	11,749
Policyholder account balances	5,023	5,100
Policyholder Dividends Payable	0	0
Unearned Premiums	1	1
Unearned Revenue	797	740
EMEA
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	1,623	1,787
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	3,639	5,215
Policyholder account balances	9,392	12,037
Policyholder Dividends Payable	0	6
Unearned Premiums	21	23
Unearned Revenue	553	555
MetLife Holdings
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	2,607	2,712
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	76,523	78,048
Policyholder account balances	27,450	28,858
Policyholder Dividends Payable	393	494
Unearned Premiums	159	154
Unearned Revenue	190	188
Corporate & Other
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
DAC and VOBA	31	31
Future Policy Benefits, Other Policy-Related Balances and Policyholder Dividend Obligation	1,240	1,475
Policyholder account balances	(19)	(16)
Policyholder Dividends Payable	0	0
Unearned Premiums	0	0
Unearned Revenue	$ 0	$ 0