Tarkio Fund Risks In General [Member] Risks Of Investing In Common Stocks [Member] Risks Of Small And Medium Capitalization Companies [Member] Risks Of Investing In Foreign Securities [Member] Risks Of Fixed Income Securities [Member] Investment Company Securities Risks [Member] Risks Of Nondiversification [Member] Sector Risk [Member] Esg Or Responsible Investing Risk [Member] Management Risks [Member] Tarkio Fund S&P 500 Index Tarkio Fund [Default Label]