Condensed Financial Information (Parent Company) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net income (loss)	$ 4,426	$ 1,578	$ 5,284
(Gains) losses on investments and from sales of businesses, net	1,165	2,800	1,260
Other, net	628	197	245
Net cash provided by (used in) operating activities	14,598	13,721	13,044
Cash flows from investing activities
Sales, maturities and repayments of fixed maturity securities available-for-sale	55,650	58,816	88,937
Sales, maturities and repayments of short-term investments	11,841	13,117	14,094
Purchases of fixed maturity securities available-for-sale	(65,667)	(63,460)	(82,956)
Purchases of short-term investments	(10,943)	(14,000)	(11,741)
Cash received in connection with freestanding derivatives	2,288	3,145	4,524
Cash paid in connection with freestanding derivatives	(3,981)	(5,662)	(7,793)
Other, net	(173)	(143)	(63)
Net cash provided by (used in) investing activities	(11,493)	(10,246)	(2,620)
Cash flows from financing activities
Net change in payables for collateral under securities loaned and other transactions	(244)	(3,283)	(10,730)
Long-term debt issued	1,568	1,989	1,013
Long-term debt repaid	(1,792)	(1,035)	(85)
Treasury stock acquired in connection with share repurchases	(3,207)	(3,103)	(3,326)
Dividends on preferred stock	(200)	(198)	(185)
Dividends on common stock	(1,527)	(1,566)	(1,598)
Other, net	223	(139)	(236)
Net cash provided by (used in) financing activities	(3,131)	(2,940)	(9,948)
Cash and cash equivalents, from continuing operations, beginning of year	20,639
Cash and cash equivalents, from continuing operations, end of year	20,068	20,639
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	1,600	1,833	1,056
Parent Company
Cash flows from operating activities
Net income (loss)	4,426	1,578	5,284
Earnings of subsidiaries	(5,056)	(2,199)	(5,619)
Dividends from subsidiaries	5,467	4,780	5,168
(Gains) losses on investments and from sales of businesses, net	(250)	(134)	(332)
Other, net	148	158	(73)
Net cash provided by (used in) operating activities	4,735	4,183	4,428
Cash flows from investing activities
Sales, maturities and repayments of fixed maturity securities available-for-sale	1,256	3,093	1,609
Sales, maturities and repayments of short-term investments	255	1,330	0
Purchases of fixed maturity securities available-for-sale	(1,389)	(973)	(2,757)
Purchases of short-term investments	(842)	(1,375)	0
Cash received in connection with freestanding derivatives	520	161	296
Cash paid in connection with freestanding derivatives	(418)	(155)	(103)
Expense paid on behalf of subsidiaries	(5)	(4)	(10)
Receipts on loans to subsidiaries	320	250	150
Issuances of loans to subsidiaries	(300)	(460)	(210)
Returns of capital from subsidiaries	74	6	8
Capital contributions to subsidiaries	(249)	(528)	(5)
Other, net	(13)	(3)	15
Net cash provided by (used in) investing activities	(791)	1,342	(1,007)
Cash flows from financing activities
Net change in payables for collateral under securities loaned and other transactions	25	111	1
Long-term debt issued	1,518	1,986	1,000
Long-term debt repaid	(1,438)	(1,000)	0
Treasury stock acquired in connection with share repurchases	(3,207)	(3,103)	(3,326)
Dividends on preferred stock	(200)	(198)	(185)
Dividends on common stock	(1,527)	(1,566)	(1,598)
Other, net	23	(24)	16
Net cash provided by (used in) financing activities	(4,806)	(3,794)	(4,092)
Change in cash and cash equivalents	(862)	1,731	(671)
Cash and cash equivalents, from continuing operations, beginning of year	3,021	1,290	1,961
Cash and cash equivalents, from continuing operations, end of year	2,159	3,021	1,290
Supplemental disclosures of cash flow information
Net cash paid for Interest	915	852	800
Net cash paid (received) for Income tax	(46)	(165)	(129)
Non-cash transactions:
Returns of capital from subsidiaries	1	2	12
Capital contributions to subsidiaries	1	1	11
Amounts paid to (received from) subsidiaries, net | Parent Company
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	(76)	(671)	(214)
Income tax paid (received) by MetLife, Inc., net | Parent Company
Supplemental disclosures of cash flow information
Net cash paid (received) for Income tax	$ 30	$ 506	$ 85