Cover |
12 Months Ended |
|---|---|
Dec. 31, 2025 | |
| Document Information [Line Items] | |
| Document Type | 11-K |
| Entity Registrant Name | FASTENAL COMPANY |
| Amendment Flag | false |
| Entity Central Index Key | 0000815556 |
| Fastenal Company & Subsidiaries 401(k) and Employee Stock Ownership Plan | |
| Document Information [Line Items] | |
| Document Type | 11-K |
| Entity Registrant Name | FASTENAL COMPANY |
| Amendment Flag | false |
| Entity Central Index Key | 0000815556 |