v3.26.1
Expense Example, No Redemption - Optimum Fund Trust Classes A, C, Institutional - C
Mar. 31, 2026
USD ($)
Optimum Large Cap Growth Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 197
Expense Example, No Redemption, 3 Years 615
Expense Example, No Redemption, 5 Years 1,060
Expense Example, No Redemption, 10 Years 2,293
Optimum Small-Mid Cap Growth Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 222
Expense Example, No Redemption, 3 Years 708
Expense Example, No Redemption, 5 Years 1,220
Expense Example, No Redemption, 10 Years 2,627
Optimum Small-Mid Cap Value Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 226
Expense Example, No Redemption, 3 Years 716
Expense Example, No Redemption, 5 Years 1,232
Expense Example, No Redemption, 10 Years 2,649
Optimum International Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 210
Expense Example, No Redemption, 3 Years 649
Expense Example, No Redemption, 5 Years 1,114
Expense Example, No Redemption, 10 Years 2,400
Optimum Fixed Income Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 182
Expense Example, No Redemption, 3 Years 563
Expense Example, No Redemption, 5 Years 970
Expense Example, No Redemption, 10 Years 2,105
Optimum Large Cap Value Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 195
Expense Example, No Redemption, 3 Years 603
Expense Example, No Redemption, 5 Years 1,037
Expense Example, No Redemption, 10 Years $ 2,243