VALUE LINE MID CAP FOCUSED FUND, INC. VALUE LINE MID CAP FOCUSED FUND, INC. Institutional Class Growth Style Risk [Member] Market Risk [Member] Equity Securities Risk [Member] Sector Allocation Risk [Member] Focused Portfolio Risk [Member] Small and Mid-Sized Company Risk [Member] Ranking System Risk [Member] Active Management Risk [Member] Market Disruption Risk [Member] Liquidity Risk [Member] Foreign Investments Risk [Member] Cybersecurity Risk [Member] S&P MidCap 400® Index (reflects no deduction for fees, expenses or taxes) S&P 500® Index (reflects no deduction for fees, expenses or taxes) Market Risk Member Ranking System Risk Member Small And Mid Sized Company Risk Member S000007570 Member Cybersecurity Risk Member index_ SP_ Mid Cap_400_ Index_reflects_no_deduction_for_fees_expenses_or_taxes Member Equity Securities Risk Member Focused Portfolio Risk Member C000193014 Member Growth Style Risk Member Active Management Risk Member index_ SP_500_ Index_reflects_no_deduction_for_fees_expenses_or_taxes Member C000020635 Member Foreign Investments Risk Member Market Disruption Risk Member Liquidity Risk Member Sector Allocation Risk Member