Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.10.0.1
Document And Entity Information - shares
3 Months Ended
Dec. 31, 2018
Jan. 30, 2019
Document Information [Line Items]    
Entity Registrant Name Clearfield, Inc.  
Entity Central Index Key 0000796505  
Trading Symbol clfd  
Current Fiscal Year End Date --09-30  
Entity Filer Category Accelerated Filer  
Entity Current Reporting Status Yes  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Common Stock, Shares Outstanding (in shares)   13,662,456
Document Type 10-Q  
Document Period End Date Dec. 31, 2018  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Amendment Flag false