v3.26.1
Average Annual Total Returns
 12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
M International Equity Fund | MSCI ACWI (All Country World Index) ex USA IMI Index      
Prospectus [Line Items]      
Average Annual Return, Percent [1] 31.96% 7.77% 8.37%
M International Equity Fund | M International Equity Fund      
Prospectus [Line Items]      
Average Annual Return, Percent 32.44% 8.77% 6.99%
M Large Cap Growth Fund | S&P 500 Index      
Prospectus [Line Items]      
Average Annual Return, Percent [2] 17.88% 14.43% 14.82%
M Large Cap Growth Fund | Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [3] 18.56% 15.32% 18.13%
M Large Cap Growth Fund | M Large Cap Growth Fund      
Prospectus [Line Items]      
Average Annual Return, Percent 19.61% 12.43% 15.06%
M Capital Appreciation Fund | S&P 500 Index      
Prospectus [Line Items]      
Average Annual Return, Percent [4] 17.88% 14.43% 14.82%
M Capital Appreciation Fund | Russell 2500 Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [5] 11.91% 7.26% 10.41%
M Capital Appreciation Fund | M Capital Appreciation Fund      
Prospectus [Line Items]      
Average Annual Return, Percent 18.06% 9.10% 11.24%
M Large Cap Value Fund | Russell 1000 Index      
Prospectus [Line Items]      
Average Annual Return, Percent [6] 17.37% 13.59% 14.59%
M Large Cap Value Fund | Russell 1000 Value Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [7] 15.91% 11.33% 10.53%
M Large Cap Value Fund | M Large Cap Value Fund      
Prospectus [Line Items]      
Average Annual Return, Percent 17.31% 13.92% 9.61%
[1] The Fund has adopted this broad-based index as its primary benchmark index and serves as the Fund’s regulatory index.
[2] The Fund has adopted this broad-based index as its primary benchmark index in response to regulatory requirements and serves as the Fund’s regulatory index.
[3] The Russell 1000® Growth Index is the Fund’s additional index and is more representative of the Fund’s risk and return than the regulatory index.
[4] The Fund has adopted this broad-based index as its primary benchmark index in response to regulatory requirements and serves as the Fund’s regulatory index.
[5] The Russell 2500® Index is the Fund’s additional index and is more representative of the Fund’s risk and return than the regulatory index.
[6] The Fund has adopted this broad-based index as its primary benchmark index in response to regulatory requirements and serves as the Fund’s regulatory index.
[7] The Russell 1000® Value Index is the Fund’s additional index and is more representative of the Fund’s risk and return than the regulatory risk.