Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.21.2
Document And Entity Information - shares
 9 Months Ended
Jun. 30, 2021
Jul. 12, 2021
Document Information [Line Items]    
Entity Central Index Key 0000796505  
Entity Registrant Name Clearfield, Inc.  
Amendment Flag false  
Current Fiscal Year End Date --09-30  
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2021  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2021  
Document Transition Report false  
Entity File Number 0-16106  
Entity Incorporation, State or Country Code MN  
Entity Tax Identification Number 41-1347235  
Entity Address, Address Line One 7050 Winnetka Avenue North, Suite 100  
Entity Address, City or Town Brooklyn Park  
Entity Address, State or Province MN  
Entity Address, Postal Zip Code 55428  
City Area Code 763  
Local Phone Number 476-6866  
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol CLFD  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   13,742,545