Segment Information (Total Assets) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Separate account assets	$ 144,634	$ 146,038
Separate account liabilities	144,634	146,038
Total assets (1),(2)	687,584	663,072
Group Benefits
Segment Reporting Information [Line Items]
Separate account assets	1,159	990
Separate account liabilities	1,159	990
Total assets (1),(2)	$ 36,715	$ 35,849
Net investment income from equity method investments	0.00%	1.00%	5.00%
Equity Method Invested Assets	1.00%
Retirement and Income Solutions
Segment Reporting Information [Line Items]
Separate account assets	$ 53,093	$ 60,040
Separate account liabilities	53,093	60,040
Total assets (1),(2)	$ 218,587	$ 216,370
Net investment income from equity method investments	1.00%	6.00%	26.00%
Equity Method Invested Assets	3.00%
Asia
Segment Reporting Information [Line Items]
Separate account assets	$ 9,187	$ 8,292
Separate account liabilities	9,187	8,292
Total assets (1),(2)	$ 157,206	$ 148,305
Net investment income from equity method investments	4.00%	12.00%	30.00%
Equity Method Invested Assets	6.00%
Latin America
Segment Reporting Information [Line Items]
Separate account assets	$ 41,320	$ 39,428
Separate account liabilities	41,320	39,428
Total assets (1),(2)	$ 69,177	$ 63,687
Net investment income from equity method investments	1.00%	3.00%	7.00%
Equity Method Invested Assets	0.00%
EMEA
Segment Reporting Information [Line Items]
Separate account assets	$ 4,327	$ 3,314
Separate account liabilities	4,327	3,314
Total assets (1),(2)	18,596	16,860
MetLife Holdings
Segment Reporting Information [Line Items]
Separate account assets	35,548	33,974
Separate account liabilities	35,548	33,974
Total assets (1),(2)	$ 148,524	$ 148,749
Net investment income from equity method investments	2.00%	6.00%	26.00%
Equity Method Invested Assets	4.00%
Corporate & Other
Segment Reporting Information [Line Items]
Separate account assets	$ 0	$ 0
Separate account liabilities	0	0
Total assets (1),(2)	$ 38,779	$ 33,252

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