v3.26.1
Average Annual Total Returns - DELAWARE GROUP EQUITY FUNDS IV - A, C, R, and Institutional
 12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Nomura Asset Strategy Fund | MSCI ACWI (All Country World Index) (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.34% 11.19% 11.72%
Nomura Asset Strategy Fund | MSCI ACWI (All Country World Index) (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.87% 11.70% 12.28%
Nomura Asset Strategy Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 9.92% 7.35% 7.61%
Nomura Asset Strategy Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 7.38% 4.73% 5.53%
Nomura Asset Strategy Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 7.36% 5.08% 5.50%
Nomura Asset Strategy Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 14.75% 7.75% 7.57%
Nomura Asset Strategy Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 16.90% 8.90% 8.53%
Nomura Asset Strategy Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 16.98% 9.01% 8.66%
Nomura Asset Strategy Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 16.31% 8.31% 7.92%
Nomura Asset Strategy Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 16.63% 8.64% 8.28%
Nomura Balanced Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Nomura Balanced Fund | Bloomberg US Aggregate Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 7.30% (0.36%) 2.01%
Nomura Balanced Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 5.30% 6.67% 7.79%
Nomura Balanced Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 4.50% 4.67% 5.93%
Nomura Balanced Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 3.49% 4.74% 5.75%
Nomura Balanced Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 9.94% 7.10% 7.78%
Nomura Balanced Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 12.03% 8.19% 8.69%
Nomura Balanced Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 12.11% 8.30% 8.83%
Nomura Balanced Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 11.44% 7.62% 8.08%
Nomura Balanced Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 11.70% 7.93% 8.43%
Nomura Core Equity Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Nomura Core Equity Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 8.70% 12.47% 13.07%
Nomura Core Equity Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 5.37% 9.20% 10.44%
Nomura Core Equity Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 7.52% 9.29% 10.08%
Nomura Core Equity Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 13.59% 12.93% 13.00%
Nomura Core Equity Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 15.64% 14.09% 14.01%
Nomura Core Equity Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 15.73% 14.18% 14.13%
Nomura Core Equity Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 15.04% 13.48% 13.36%
Nomura Core Equity Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 15.35% 13.86% 13.90%
Nomura Global Growth Fund | MSCI ACWI (All Country World Index) (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.34% 11.19% 11.72%
Nomura Global Growth Fund | MSCI ACWI (All Country World Index) (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.87% 11.70% 12.28%
Nomura Global Growth Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 11.07% 8.48% 9.87%
Nomura Global Growth Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 8.90% 4.91% 7.42%
Nomura Global Growth Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 8.09% 5.83% 7.41%
Nomura Global Growth Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 15.97% 8.86% 9.78%
Nomura Global Growth Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 18.16% 10.03% 10.82%
Nomura Global Growth Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 18.28% 10.13% 10.96%
Nomura Global Growth Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 17.57% 9.45% 10.20%
Nomura Global Growth Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 17.84% 9.77% 10.54%
Nomura International Core Equity Fund | MSCI ACWI (All Country World Index) ex USA (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 32.39% 7.91% 8.41%
Nomura International Core Equity Fund | MSCI ACWI (All Country World Index) ex USA (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 33.11% 8.46% 8.95%
Nomura International Core Equity Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 16.85% 6.41% 5.86%
Nomura International Core Equity Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 14.02% 5.54% 5.01%
Nomura International Core Equity Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 12.28% 4.96% 4.51%
Nomura International Core Equity Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 22.02% 6.90% 5.90%
Nomura International Core Equity Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 24.32% 8.02% 6.86%
Nomura International Core Equity Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 24.45% 8.08% 6.92%
Nomura International Core Equity Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 23.70% 7.39% 6.19%
Nomura International Core Equity Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 23.98% 7.71% 6.53%
Nomura Large Cap Growth Fund | Russell 1000 Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.37% 13.59% 14.59%
Nomura Large Cap Growth Fund | Russell 1000 Growth Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [1] 18.56% 15.32% 18.13%
Nomura Large Cap Growth Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 2.58% 10.73% 14.75%
Nomura Large Cap Growth Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 0.69% 8.92% 12.73%
Nomura Large Cap Growth Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 2.88% 8.08% 11.66%
Nomura Large Cap Growth Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 7.07% 11.17% 14.71%
Nomura Large Cap Growth Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 9.12% 12.36% 15.75%
Nomura Large Cap Growth Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 9.20% 12.41% 15.83%
Nomura Large Cap Growth Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 8.57% 11.72% 15.05%
Nomura Large Cap Growth Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 8.84% 12.05% 15.45%
Nomura Mid Cap Growth Fund | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.15% 13.15% 14.29%
Nomura Mid Cap Growth Fund | Russell Midcap Growth Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [2] 8.66% 6.65% 12.49%
Nomura Mid Cap Growth Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent (4.96%) (1.20%) 10.00%
Nomura Mid Cap Growth Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent (7.19%) (3.36%) 7.88%
Nomura Mid Cap Growth Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent (1.30%) (0.94%) 7.96%
Nomura Mid Cap Growth Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent (0.76%) (0.78%) 9.99%
Nomura Mid Cap Growth Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 1.12% 0.27% 11.00%
Nomura Mid Cap Growth Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 1.24% 0.32% 11.07%
Nomura Mid Cap Growth Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 0.59% (0.32%) 10.31%
Nomura Mid Cap Growth Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 0.84% (0.02%) 10.67%
Nomura Mid Cap Income Opportunities Fund | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.15% 13.15% 14.29%
Nomura Mid Cap Income Opportunities Fund | Russell Midcap Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [3] 10.60% 8.67% 11.01%
Nomura Mid Cap Income Opportunities Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 1.97% 6.84% 9.51%
Nomura Mid Cap Income Opportunities Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent (1.29%) 4.99% 8.29%
Nomura Mid Cap Income Opportunities Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 3.41% 5.20% 7.62%
Nomura Mid Cap Income Opportunities Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 6.37% 7.29% 9.51%
Nomura Mid Cap Income Opportunities Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 8.45% 8.43% 10.51%
Nomura Mid Cap Income Opportunities Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 8.60% 8.49% 10.58%
Nomura Mid Cap Income Opportunities Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 7.91% 7.80% 9.81%
Nomura Mid Cap Income Opportunities Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 8.17% 8.11% 10.16%
Nomura Smid Cap Core Fund | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [4] 17.15% 13.15% 14.29%
Nomura Smid Cap Core Fund | Russell 2500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 11.91% 7.26% 10.40%
Nomura Smid Cap Core Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 2.42% 7.04% 9.28%
Nomura Smid Cap Core Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 1.98% 4.53% 7.37%
Nomura Smid Cap Core Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 1.73% 4.77% 6.93%
Nomura Smid Cap Core Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 6.91% 7.52% 9.30%
Nomura Smid Cap Core Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 8.95% 8.66% 10.34%
Nomura Smid Cap Core Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 9.07% 8.72% 10.41%
Nomura Smid Cap Core Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 8.37% 8.03% 9.65%
Nomura Smid Cap Core Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 8.63% 8.33% 9.98%
Nomura Small Cap Growth Fund | Russell 3000 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.15% 13.15% 14.29%
Nomura Small Cap Growth Fund | Russell 2000 Growth Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent [5] 13.01% 3.18% 9.57%
Nomura Small Cap Growth Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 7.07% 0.83% 9.16%
Nomura Small Cap Growth Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 2.76% (2.29%) 6.26%
Nomura Small Cap Growth Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 7.31% 0.29% 6.94%
Nomura Small Cap Growth Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 11.61% 1.24% 9.17%
Nomura Small Cap Growth Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 13.83% 2.32% 10.16%
Nomura Small Cap Growth Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 13.93% 2.38% 10.24%
Nomura Small Cap Growth Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 13.25% 1.73% 9.49%
Nomura Small Cap Growth Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 13.50% 2.03% 9.84%
Nomura Systematic Emerging Markets Equity Fund | MSCI Emerging Markets Index (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 33.57% 4.20% 8.42%
Nomura Systematic Emerging Markets Equity Fund | MSCI Emerging Markets Index (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 34.36% 4.67% 8.86%
Nomura Systematic Emerging Markets Equity Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 19.29% (0.28%) 7.49%
Nomura Systematic Emerging Markets Equity Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 17.48% (1.25%) 6.89%
Nomura Systematic Emerging Markets Equity Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 14.04% (0.04%) 6.16%
Nomura Systematic Emerging Markets Equity Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 24.60% 0.19% 7.51%
Nomura Systematic Emerging Markets Equity Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 26.93% 1.23% 8.52%
Nomura Systematic Emerging Markets Equity Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 27.13% 1.33% 8.60%
Nomura Systematic Emerging Markets Equity Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 26.31% 0.66% 7.85%
Nomura Systematic Emerging Markets Equity Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 26.59% 0.92% 8.18%
Nomura Climate Solutions Fund | MSCI ACWI (All Country World Index) (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.34% 11.19% 11.72%
Nomura Climate Solutions Fund | MSCI ACWI (All Country World Index) (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.87% 11.70% 12.28%
Nomura Climate Solutions Fund | MSCI ACWI Investable Market Index (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.06% 10.75% 11.45%
Nomura Climate Solutions Fund | MSCI ACWI Investable Market Index (gross) (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 22.60% 11.26% 11.99%
Nomura Climate Solutions Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 15.57% 16.68% 0.54%
Nomura Climate Solutions Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 15.31% 16.24% 0.30%
Nomura Climate Solutions Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 9.40% 13.46% 0.37%
Nomura Climate Solutions Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 20.69% 17.22% 0.58%
Nomura Climate Solutions Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 22.83% 18.43% 1.47%
Nomura Climate Solutions Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 23.03% 18.53% 1.56%
Nomura Climate Solutions Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 22.32% 17.74% 0.84%
Nomura Climate Solutions Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 22.57% 18.06% 1.17%
Nomura Natural Resources Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Nomura Natural Resources Fund | S&P Global Natural Resources Index (net) (reflects no deduction for fees or expenses)      
Prospectus [Line Items]      
Average Annual Return, Percent 28.86% 10.60% 10.38%
Nomura Natural Resources Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 30.06% 14.20% 6.08%
Nomura Natural Resources Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 30.06% 13.48% 5.66%
Nomura Natural Resources Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 17.80% 11.18% 4.72%
Nomura Natural Resources Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 36.00% 14.73% 6.14%
Nomura Natural Resources Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 38.26% 15.98% 7.20%
Nomura Natural Resources Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 38.52% 16.10% 7.35%
Nomura Natural Resources Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 37.64% 15.37% 6.61%
Nomura Natural Resources Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 37.93% 15.69% 6.94%
Nomura Real Estate Securities Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Nomura Real Estate Securities Fund | FTSE Nareit Equity REITs Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 2.88% 6.63% 5.70%
Nomura Real Estate Securities Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 0.49% 4.98% 4.68%
Nomura Real Estate Securities Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent (4.56%) 0.58% 1.39%
Nomura Real Estate Securities Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 3.27% 3.27% 3.05%
Nomura Real Estate Securities Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 5.00% 5.36% 4.62%
Nomura Real Estate Securities Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 6.97% 6.53% 5.65%
Nomura Real Estate Securities Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 7.13% 6.65% 5.79%
Nomura Real Estate Securities Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 6.33% 5.95% 5.04%
Nomura Real Estate Securities Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 6.63% 6.26% 5.40%
Nomura Science and Technology Fund | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 17.88% 14.42% 14.82%
Nomura Science and Technology Fund | S&P North American Technology Sector Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 27.82% 18.02% 22.54%
Nomura Science and Technology Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 26.10% 12.70% 16.89%
Nomura Science and Technology Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 21.42% 7.46% 13.13%
Nomura Science and Technology Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 18.75% 8.60% 13.00%
Nomura Science and Technology Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 31.78% 13.13% 16.86%
Nomura Science and Technology Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 34.15% 14.30% 17.86%
Nomura Science and Technology Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 34.22% 14.42% 18.00%
Nomura Science and Technology Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 33.46% 13.69% 17.19%
Nomura Science and Technology Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 33.80% 14.04% 17.59%
Nomura Global Bond Fund | Bloomberg Global Aggregate Index (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 8.17% (2.15%) 1.26%
Nomura Global Bond Fund | Bloomberg Global Aggregate Index, Hedged to USD (reflects no deduction for fees, expenses or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 4.86% 0.34% 2.39%
Nomura Global Bond Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent (0.24%) (0.55%) 2.47%
Nomura Global Bond Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent (1.73%) (1.82%) 1.32%
Nomura Global Bond Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent (0.16%) (0.97%) 1.40%
Nomura Global Bond Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 2.64% (0.13%) 2.47%
Nomura Global Bond Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 4.70% 0.86% 3.34%
Nomura Global Bond Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 4.83% 0.94% 3.38%
Nomura Global Bond Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 4.19% 0.30% 2.67%
Nomura Global Bond Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 4.44% 0.61% 3.08%
Nomura High Income Fund | Bloomberg US Aggregate Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 7.30% (0.36%) 2.01%
Nomura High Income Fund | ICE BofA US High Yield Constrained Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 8.50% 4.50% 6.44%
Nomura High Income Fund | A      
Prospectus [Line Items]      
Average Annual Return, Percent 0.96% 2.29% 4.88%
Nomura High Income Fund | A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent (1.61%) (0.42%) 1.97%
Nomura High Income Fund | A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 0.52% 0.53% 2.42%
Nomura High Income Fund | C      
Prospectus [Line Items]      
Average Annual Return, Percent 3.89% 2.75% 4.90%
Nomura High Income Fund | Institutional      
Prospectus [Line Items]      
Average Annual Return, Percent 5.93% 3.76% 5.75%
Nomura High Income Fund | R6      
Prospectus [Line Items]      
Average Annual Return, Percent 6.20% 3.89% 5.90%
Nomura High Income Fund | R      
Prospectus [Line Items]      
Average Annual Return, Percent 5.40% 3.21% 5.16%
Nomura High Income Fund | Y      
Prospectus [Line Items]      
Average Annual Return, Percent 5.67% 3.51% 5.50%
[1]
  Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell® is a trademark of Frank Russell Company.
[2]
  Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell® is a trademark of Frank Russell Company.
[3]
  Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell® is a trademark of Frank Russell Company.
[4]
  Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell® is a trademark of Frank Russell Company.
[5]
  Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell® is a trademark of Frank Russell Company.