| Cover | Aug. 09, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 9, 2021 |
| Entity File Number | 001-38908 |
| Entity Registrant Name | DRAFTKINGS INC. |
| Entity Central Index Key | 0001772757 |
| Entity Tax Identification Number | 84-4052441 |
| Entity Incorporation, State or Country Code | NV |
| Entity Address, Address Line One | 222 Berkeley Street |
| Entity Address, Address Line Two | 5th Floor |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02116 |
| City Area Code | 617 |
| Local Phone Number | 986-6744 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A common stock, par value $0.0001 per share |
| Trading Symbol | DKNG |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
