v3.26.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2026
May 12, 2026
Cover [Abstract]    
Document Type 10-Q  
Entity Registrant Name Metropolitan Life Insurance Co  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 000-55029  
Entity Incorporation, State or Country Code NY  
Entity Tax Identification Number 13-5581829  
Entity Address, Address Line One 200 Park Avenue,  
Entity Address, City or Town New York,  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10166-0188  
City Area Code 212  
Local Phone Number 578-9500  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Central Index Key 0000937834  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   494,466,664
Amendment Flag false  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --12-31