Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Sep. 30, 2022
Nov. 01, 2022
Mar. 31, 2022
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 FY    
Document Fiscal Year Focus 2022    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 30, 2022    
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 Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 747,737,778
Entity Common Stock, Shares Outstanding   13,818,452  
Auditor Firm ID 23    
Auditor Name Baker Tilly US, LLP    
Auditor Location Minneapolis, Minnesota