Condensed Financial Information (Parent Company) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income (loss)	$ 2,539	$ 6,554	$ 5,407
(Gains) losses on investments and from sales of businesses, net	1,262	(1,529)	110
Other, net	245	138	351
Net cash provided by (used in) operating activities	13,204	12,596	11,639
Cash flows from investing activities
Sales and maturities of fixed maturity securities available-for-sale	88,937	88,839	77,979
Purchases of fixed maturity securities available-for-sale	(82,956)	(97,368)	(89,633)
Cash received in connection with freestanding derivatives	4,524	3,453	4,847
Cash paid in connection with freestanding derivatives	(7,793)	(7,990)	(4,247)
Other, net	(28)	(46)	139
Net cash provided by (used in) investing activities	(2,620)	(11,187)	(18,569)
Cash flows from financing activities
Net change in payables for collateral under securities loaned and other transactions	(10,730)	1,883	3,538
Long-term debt issued	1,013	29	1,124
Long-term debt repaid	(85)	(582)	(99)
Treasury stock acquired in connection with share repurchases	(3,326)	(4,303)	(1,151)
Preferred stock issued, net of issuance costs	0	0	1,961
Redemption of preferred stock	0	(494)	(989)
Preferred stock redemption premium	0	(6)	(14)
Dividends on preferred stock	(185)	(195)	(202)
Dividends on common stock	(1,598)	(1,647)	(1,657)
Other, net	(236)	22	191
Net cash provided by (used in) financing activities	(10,108)	(1,375)	10,729
Cash and cash equivalents, from continuing operations, beginning of year	20,047
Cash and cash equivalents, from continuing operations, end of year	20,195	20,047
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	1,056	1,102	787
Parent Company
Cash flows from operating activities
Net income (loss)	2,539	6,554	5,407
Earnings of subsidiaries	(2,874)	(5,995)	(6,263)
Dividends from subsidiaries	5,168	4,830	3,970
(Gains) losses on investments and from sales of businesses, net	(332)	(1,655)	154
Other, net	(73)	23	211
Net cash provided by (used in) operating activities	4,428	3,757	3,479
Cash flows from investing activities
Sales and maturities of fixed maturity securities available-for-sale	1,609	5,078	3,693
Purchases of fixed maturity securities available-for-sale	(2,757)	(4,371)	(3,858)
Cash received in connection with freestanding derivatives	296	111	71
Cash paid in connection with freestanding derivatives	(103)	(27)	(100)
Sales of businesses	0	3,902	0
Purchases of businesses	0	0	(1,875)
Expense paid on behalf of subsidiaries	(10)	(15)	(15)
Receipts on loans to subsidiaries	150	195	100
Issuances of loans to subsidiaries	(210)	(230)	0
Returns of capital from subsidiaries	8	13	16
Capital contributions to subsidiaries	(5)	(88)	(422)
Net change in short-term investments	0	156	4
Other, net	15	9	(2)
Net cash provided by (used in) investing activities	(1,007)	4,733	(2,388)
Cash flows from financing activities
Net change in payables for collateral under securities loaned and other transactions	1	88	49
Long-term debt issued	1,000	496	1,246
Long-term debt repaid	0	(996)	(251)
Treasury stock acquired in connection with share repurchases	(3,326)	(4,303)	(1,151)
Preferred stock issued, net of issuance costs	0	0	1,961
Redemption of preferred stock	0	(494)	(989)
Preferred stock redemption premium	0	(6)	(14)
Dividends on preferred stock	(185)	(195)	(202)
Dividends on common stock	(1,598)	(1,647)	(1,657)
Other, net	16	87	(19)
Net cash provided by (used in) financing activities	(4,092)	(6,970)	(1,027)
Change in cash and cash equivalents	(671)	1,520	64
Cash and cash equivalents, from continuing operations, beginning of year	1,961	441	377
Cash and cash equivalents, from continuing operations, end of year	1,290	1,961	441
Supplemental disclosures of cash flow information
Net cash paid for Interest	800	853	815
Net cash paid (received) for Income tax	(129)	18	(296)
Non-cash transactions:
Dividends from subsidiary	0	14	341
Returns of capital from subsidiaries	12	7	13
Capital contributions to subsidiaries	11	15	1
Amounts paid to (received from) subsidiaries, net | Parent Company
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	(214)	(110)	(392)
Income tax paid (received) by MetLife, Inc., net | Parent Company
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	$ 85	$ 128	$ 96