| Cover | Oct. 26, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 26, 2020 |
| Entity File Number | 001-35092 |
| Entity Registrant Name | EXACT SCIENCES CORPORATION |
| Entity Central Index Key | 0001124140 |
| Entity Tax Identification Number | 02-0478229 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 5505 Endeavor Lane |
| Entity Address, City or Town | Madison |
| Entity Address, State or Province | WI |
| Entity Address, Postal Zip Code | 53719 |
| City Area Code | 608 |
| Local Phone Number | 284-5700 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value per share |
| Trading Symbol | EXAS |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
