v3.26.1
Average Annual Total Returns
 12 Months Ended 60 Months Ended 101 Months Ended 120 Months Ended
Jun. 18, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
 [1]
Dec. 31, 2025
VALUE LINE MID CAP FOCUSED FUND, INC.          
Prospectus [Line Items]          
Average Annual Return, Percent   0.80% 7.51%   12.49%
VALUE LINE MID CAP FOCUSED FUND, INC. | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Percent   0.29% 6.61%   11.55%
VALUE LINE MID CAP FOCUSED FUND, INC. | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Percent   0.83% 5.78%   10.22%
Institutional Class          
Prospectus [Line Items]          
Average Annual Return, Percent   1.02% 7.77% 12.38%  
Performance Inception Date Aug. 14, 2017        
S&P MidCap 400® Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent   7.50% 9.12% 9.90% 10.72%
S&P 500® Index (reflects no deduction for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent   17.88% 14.42% 14.98% 14.82%
[1] Institutional Class inception date.