v3.25.4
Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 02, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Financial Statement Error Correction [Flag] false    
Entity Interactive Data Current Yes    
ICFR Auditor Attestation Flag true    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Information [Line Items]      
Entity Registrant Name DONEGAL GROUP INC    
Entity Central Index Key 0000800457    
Entity File Number 0-15341    
Entity Tax Identification Number 23-2424711    
Entity Incorporation, State or Country Code DE    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Shell Company false    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Public Float     $ 355,484,764
Entity Contact Personnel [Line Items]      
Entity Address, Address Line One 1195 River Road    
Entity Address, City or Town Marietta    
Entity Address, State or Province PA    
Entity Address, Postal Zip Code 17547    
Entity Phone Fax Numbers [Line Items]      
City Area Code 800    
Local Phone Number 877-0600    
Class A Common Stock [Member]      
Entity Listings [Line Items]      
Title of 12(b) Security Class A Common Stock, $.01 par value    
Trading Symbol DGICA    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   31,426,189  
Class B Common Stock [Member]      
Entity Listings [Line Items]      
Title of 12(b) Security Class B Common Stock, $.01 par value    
Trading Symbol DGICB    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   5,576,775