| Document and Entity Information | Feb. 26, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001316835 |
| Document Type | 8-K |
| Document Period End Date | Feb. 26, 2021 |
| Entity Registrant Name | BUILDERS FIRSTSOURCE, INC. |
| Entity File Number | 0-51357 |
| Entity Incorporation State Country Code | DE |
| Entity Tax Identification Number | 52-2084569 |
| Entity Address, Address Line One | 2001 Bryan Street |
| Entity Address, Address Line Two | Suite 1600 |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75201 |
| City Area Code | (214) |
| Local Phone Number | 880-3500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.01 per share |
| Trading Symbol | BLDR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
