v3.26.1
Average Annual Total Returns - DELAWARE GROUP EQUITY FUNDS IV - A, C, R, and Institutional - Nomura Healthcare Fund
 12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Russell 3000 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.15% 13.15% 14.29%
Russell 3000 Healthcare Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [1] 14.56% 6.31% 9.54%
A      
Prospectus [Line Items]      
Average Annual Return, Percent 15.07% 6.21% 9.48%
A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 12.13% 4.10% 7.69%
A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 10.65% 4.54% 7.32%
C      
Prospectus [Line Items]      
Average Annual Return, Percent 20.20% 6.68% 9.31%
R      
Prospectus [Line Items]      
Average Annual Return, Percent 21.79% 7.21% 9.85%
Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 22.38% 7.75% 10.41%
[1]
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