Investments (Securities Lending and Repurchase Agreements Remaining Tenor) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	$ 6,515	$ 6,202
Repurchase Agreements
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	2,975	2,975
U.S. government and agency
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	6,515	6,202
U.S. government and agency \| Open (1)
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	1,726	1,767
U.S. government and agency \| 1 Month or Less
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	2,765	3,023
U.S. government and agency \| Over 1 Month to 6 Months
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	2,024	1,412
U.S. government and agency \| Over 6 Months to 1 Year
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	0	0
U.S. government and agency \| Repurchase Agreements
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	2,975	2,975
U.S. government and agency \| Repurchase Agreements \| Open (1)
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	0	0
U.S. government and agency \| Repurchase Agreements \| 1 Month or Less
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	2,975	2,975
U.S. government and agency \| Repurchase Agreements \| Over 1 Month to 6 Months
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	0	0
U.S. government and agency \| Repurchase Agreements \| Over 6 Months to 1 Year
Securities Financing Transaction [Line Items]
Cash collateral on deposit from counterparties	$ 0	$ 0

METROPOLITAN LIFE INSURANCE CO 10-Q