v3.26.3
Average Annual Total Returns - Tarkio Fund
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2025
Dec. 31, 2025
Prospectus [Line Items]                        
Average Annual Return, Percent 30.33%                   11.69% 13.79%
After Taxes on Distributions                        
Prospectus [Line Items]                        
Average Annual Return, Percent 28.74%                   10.56% 12.87%
After Taxes on Distributions and Sales                        
Prospectus [Line Items]                        
Average Annual Return, Percent 19.13%                   9.01% 11.27%
S&P 500 Index                        
Prospectus [Line Items]                        
Average Annual Return, Percent 17.88%                   14.42% 14.81%
Tarkio Fund                        
Prospectus [Line Items]                        
Average Annual Return, Percent 30.33% 21.72% 26.34% (30.31%) 24.41% 27.00% 29.57% (23.27%) 29.04% 28.50%