v3.26.1
Note 3 - Investments (Details Textual)
 3 Months Ended 6 Months Ended
Jun. 30, 2025
$ / shares
shares
Jun. 30, 2026
USD ($)
$ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
Jun. 30, 2026
USD ($)
$ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
Dec. 31, 2025
USD ($)
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures   $ 18,856,000   $ 18,856,000   $ 18,841,000
Equity in Earnings of Related Parties Equity Method Investees       15,000 $ (41,000)  
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments   0   0    
Fair Value, Nonrecurring [Member]            
Assets, Fair Value Disclosure   0   0    
Related Party [Member]            
Investments           1,100,000
Equity Securities, FV-NI, Gain (Loss)   274,000 $ 240,000 429,000 485,000  
Related Party [Member] | Accounts Receivable [Member]            
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval   544,000   544,000   526,000
Related Party [Member] | Accounts Payable [Member]            
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval   $ 15,000   $ 15,000   355,000
HC Government Realty Trust, Inc [Member]            
Ownership Percentage   28.00%   28.00%    
HC Government Realty Trust, Inc [Member] | Series B Cumulative Convertible Preferred Stock [Member]            
Equity Method Investment, Aggregate Cost   $ 10,250,000   $ 10,250,000    
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares   $ 10   $ 10    
Convertible Preferred Stock, Maximum Conversion Price (in dollars per share) | $ / shares   $ 9.1   $ 9.1    
HC Government Realty Trust, Inc [Member] | Common Stock of Investee [Member]            
Equity Method Investment, Other-than-Temporary Impairment   $ 0 $ 0 $ 0 $ 41,000  
Investments   $ 1,100,000   $ 1,100,000    
HC Government Realty Trust, Inc [Member] | Common Stock of Investee [Member]            
Investment Owned, Balance, Shares (in shares) | shares   250   250    
HC Government Realty Trust, Inc [Member] | Series B Cumulative Convertible Preferred Stock [Member]            
Investment Owned, Balance, Shares (in shares) | shares   1,025,000   1,025,000    
ACMAT Corporation [Member]            
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures   $ 12,600,000   $ 12,600,000   $ 12,600,000
Equity in Earnings of Related Parties Equity Method Investees   $ (71,000)   $ 15,000    
Assignment and Contribution Agreement [Member]            
Stock Issued During Period, Shares, New Issues (in shares) | shares 2,899,876          
Assignment and Contribution Agreement [Member] | ACMAT Common Stock [Member]            
Stock Issued During Period, Shares, New Issues (in shares) | shares 10,203          
Common Stock, No Par Value (in dollars per share) | $ / shares $ 0   $ 0   $ 0  
Votes Per Share 1   1   1  
Assignment and Contribution Agreement [Member] | ACMAT Class A Stock [Member]            
Stock Issued During Period, Shares, New Issues (in shares) | shares 291,656          
Common Stock, No Par Value (in dollars per share) | $ / shares $ 0   $ 0   $ 0  
Votes Per Share 10   10   10  
Assignment and Contribution Agreement [Member] | ACMAT Corporation [Member]            
Subsidiary, Ownership Percentage, Parent 39.10%   39.10%   39.10%  
Investment, Voting Power 10.40%   10.40%   10.40%