v3.19.2
Cover - shares
6 Months Ended
Jun. 30, 2019
Jul. 22, 2019
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 0-19034  
Entity Incorporation, State or Country Code NY  
Entity Tax Identification Number 13-3444607  
Entity Address, Address Line One 777 Old Saw Mill River Road  
Entity Address, City or Town Tarrytown,  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10591-6707  
City Area Code 914  
Local Phone Number 847-7000  
Title of 12(b) Security Common Stock - par value $.001 per share  
Trading Symbol REGN  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Registrant Name REGENERON PHARMACEUTICALS, INC.  
Entity Central Index Key 0000872589  
Current Fiscal Year End Date --12-31  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Common Stock    
Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   107,983,401
Class A Stock    
Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   1,848,970