v3.26.3
S000010412 [Member] Average Annual Total Returns
 12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
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%
Russell 2500® Value Index (reflects no deduction for fees, expenses, or taxes)      
Prospectus [Line Items]      
Average Annual Return, Percent 12.73% 10.02% 9.72%
Class A      
Prospectus [Line Items]      
Average Annual Return, Percent [1] (1.81%) 7.30% 7.64%
Class A | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent [1] (3.09%) 5.04% 5.87%
Class A | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent [1] (0.11%) 5.37% 5.81%
Class C      
Prospectus [Line Items]      
Average Annual Return, Percent 0.80% 7.44% 7.29%
Advisor Class      
Prospectus [Line Items]      
Average Annual Return, Percent 2.80% 8.52% 8.38%
Class I      
Prospectus [Line Items]      
Average Annual Return, Percent 2.68% 8.46% 8.35%
Class Z      
Prospectus [Line Items]      
Average Annual Return, Percent 2.78% 8.54% 8.43%
[1] After-tax returns: – Are shown for Class A shares only and will vary for the other Classes of shares because these Classes have different expense ratios; – Are estimates based on the highest historical individual federal marginal income tax rates, and do not reflect the impact of state and local taxes; actual after-tax returns depend on an individual investor’s tax situation and are likely to differ from those shown; and – Are not relevant to investors who hold fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.