v3.25.2
Shareholder Report
6 Months Ended
Jun. 30, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name T. ROWE PRICE DIVERSIFIED MID-CAP GROWTH FUND, INC.
Entity Central Index Key 0001267862
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2025
C000005433  
Shareholder Report [Line Items]  
Fund Name Diversified Mid-Cap Growth Fund
Class Name Investor Class
Trading Symbol PRDMX
Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Diversified Mid-Cap Growth Fund (the "fund") for the period of January 1, 2025 to June 30, 2025. You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary. 

Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
Additional Information [Text Block] You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary.
Material Fund Change Notice [Text Block]  
Additional Information Phone Number 1‑800‑638‑5660
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 17.3333px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">info@troweprice.com</span>
Additional Information Website www.troweprice.com/prospectus
Expenses [Text Block]

What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)

 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Diversified Mid-Cap Growth Fund - Investor Class
$44
0.85%
Expenses Paid, Amount $ 44
Expense Ratio, Percent 0.85%
Updated Performance Information Location [Text Block]

If you invest directly with T. Rowe Price, you can elect to receive future shareholder reports or other important documents through electronic delivery by enrolling at www.troweprice.com/paperless. If you invest through a financial intermediary such as an investment advisor, a bank, retirement plan sponsor or a brokerage firm, please contact that organization and ask if it can provide electronic delivery.

Visit www.troweprice.com/en/us/market-data-disclosures for additional legal notices & disclaimers.

AssetsNet $ 3,659,591,000
Holdings Count | Holding 274
InvestmentCompanyPortfolioTurnover 33.70%
Additional Fund Statistics [Text Block]

What are some fund statistics?

Fund Statistics

Total Net Assets (000s)
$3,659,591
Number of Portfolio Holdings
274
Additional Fund Statistics Significance or Limits [Text Block]
Portfolio Turnover Rate
33.7%
Holdings [Text Block]

Sector Allocation (as a % of Net Assets)

Industrials & Business Services
19.6%
Information Technology
19.2
Consumer Discretionary
18.3
Health Care
14.1
Financials
10.1
Communication Services
6.3
Energy
4.0
Utilities
3.2
Consumer Staples
2.9
Other
2.3
Largest Holdings [Text Block]

Top Ten Holdings (as a % of Net Assets)

Royal Caribbean Cruises
2.4%
Howmet Aerospace
2.4
Vistra
2.3
Cencora
2.2
Hilton Worldwide Holdings
2.0
Cloudflare
1.9
ROBLOX
1.9
Axon Enterprise
1.9
Vertiv Holdings
1.7
Ameriprise Financial
1.6
Material Fund Change [Text Block]
Updated Prospectus Web Address www.troweprice.com/paperless
C000190557  
Shareholder Report [Line Items]  
Fund Name Diversified Mid-Cap Growth Fund
Class Name I Class
Trading Symbol RPTTX
Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Diversified Mid-Cap Growth Fund (the "fund") for the period of January 1, 2025 to June 30, 2025. You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary. 

Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
Additional Information [Text Block] You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary.
Material Fund Change Notice [Text Block]  
Additional Information Phone Number 1‑800‑638‑5660
Additional Information Email <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 17.3333px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">info@troweprice.com</span>
Additional Information Website www.troweprice.com/prospectus
Expenses [Text Block]

What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)

 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Diversified Mid-Cap Growth Fund - I Class
$35
0.68%
Expenses Paid, Amount $ 35
Expense Ratio, Percent 0.68%
Updated Performance Information Location [Text Block]

If you invest directly with T. Rowe Price, you can elect to receive future shareholder reports or other important documents through electronic delivery by enrolling at www.troweprice.com/paperless. If you invest through a financial intermediary such as an investment advisor, a bank, retirement plan sponsor or a brokerage firm, please contact that organization and ask if it can provide electronic delivery.

Visit www.troweprice.com/en/us/market-data-disclosures for additional legal notices & disclaimers.

AssetsNet $ 3,659,591,000
Holdings Count | Holding 274
InvestmentCompanyPortfolioTurnover 33.70%
Additional Fund Statistics [Text Block]

What are some fund statistics?

Fund Statistics

Total Net Assets (000s)
$3,659,591
Number of Portfolio Holdings
274
Additional Fund Statistics Significance or Limits [Text Block]
Portfolio Turnover Rate
33.7%
Holdings [Text Block]

Sector Allocation (as a % of Net Assets)

Industrials & Business Services
19.6%
Information Technology
19.2
Consumer Discretionary
18.3
Health Care
14.1
Financials
10.1
Communication Services
6.3
Energy
4.0
Utilities
3.2
Consumer Staples
2.9
Other
2.3
Largest Holdings [Text Block]

Top Ten Holdings (as a % of Net Assets)

Royal Caribbean Cruises
2.4%
Howmet Aerospace
2.4
Vistra
2.3
Cencora
2.2
Hilton Worldwide Holdings
2.0
Cloudflare
1.9
ROBLOX
1.9
Axon Enterprise
1.9
Vertiv Holdings
1.7
Ameriprise Financial
1.6
Material Fund Change [Text Block]
Updated Prospectus Web Address www.troweprice.com/paperless