S000000852 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell Midcap® Growth Index (reflects no deduction for fees, expenses or taxes) | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 8.66% | 6.65% | 12.49% |
| Russell 1000® Index (reflects no deduction for fees, expenses or taxes) | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.37% | 13.59% | 14.59% |
| Investor Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 9.19% | 3.54% | 8.98% |
| Investor Shares | After Taxes on Distributions | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.42% | 2.06% | 7.49% |
| Investor Shares | After Taxes on Distributions and Sales | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 8.24% | 2.67% | 7.07% |
| Institutional Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 9.34% | 3.67% | 9.12% |