| Cover | Aug. 06, 2019 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Aug. 6, 2019 |
| Entity Registrant Name | REGENERON PHARMACEUTICALS, INC. |
| Entity Central Index Key | 0000872589 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | NY |
| Entity File Number | 000-19034 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock - par value $.001 per share |
| Trading Symbol | REGN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
