v3.26.1
Shareholder Report, Average Annual Return (Details)
12 Months Ended 60 Months Ended 120 Months Ended
Feb. 28, 2026
Feb. 28, 2026
Feb. 28, 2026
C000029067      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name CM Advisors Fixed Income Fund    
Without Sales Load [Member] | C000029067      
Average Annual Return [Line Items]      
Average Annual Return, Percent 9.38% 4.76% 3.65%
Bloomberg U.S. Aggregate Bond Index      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Aggregate Bond Index    
Average Annual Return, Percent 6.26% 0.42% 1.97%