XML 17 R1.htm IDEA: XBRL DOCUMENT v3.20.4
Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2020
Feb. 28, 2021
Jun. 30, 2020
Document Information [Line Items]      
Entity Central Index Key 0000042682    
Entity Registrant Name GORMAN RUPP CO    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2020    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Document Transition Report false    
Entity File Number 1-6747    
Entity Incorporation, State or Country Code OH    
Entity Tax Identification Number 34-0253990    
Entity Address, Address Line One 600 South Airport Road    
Entity Address, City or Town Mansfield    
Entity Address, State or Province OH    
Entity Address, Postal Zip Code 44903    
City Area Code 419    
Local Phone Number 755-1011    
Title of 12(b) Security Common Shares, without par value    
Trading Symbol GRC    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 621,510,000
Entity Common Stock, Shares Outstanding   26,109,185