XML 15 R1.htm IDEA: XBRL DOCUMENT v3.22.0.1
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Feb. 28, 2022
Jun. 30, 2021
Cover [Abstract]      
Entity Central Index Key 0001681206    
Document Fiscal Period Focus FY    
Amendment Flag false    
Document Type 10-K    
Document Annual Report true    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2021    
Document Period End Date Dec. 31, 2021    
Document Transition Report false    
Entity File Number 001-37973    
Entity Registrant Name NI HOLDINGS, INC.    
Entity Incorporation, State or Country Code ND    
Entity Tax Identification Number 81-2683619    
Entity Address, Address Line One 1101 First Avenue North    
Entity Address, City or Town Fargo    
Entity Address, State or Province ND    
Entity Address, Postal Zip Code 58102    
City Area Code 701    
Local Phone Number 298-4200    
Title of 12(b) Security Common Stock, $0.01 par value per share    
Trading Symbol NODK    
Name of Exchange on which Security is Registered NASDAQ    
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 true    
Entity Ex Transition Period false    
Auditor Attestation Flag false    
Entity Shell Company false    
Entity Public Float     $ 160
Entity Common Stock, Shares Outstanding   21,196,523  
Auditor Name Mazars USA LLP    
Auditor Location Fort Washington, Pennsylvania    
Auditor Firm Id 339