v3.26.1
Shareholder Report
6 Months Ended
Apr. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Federated Hermes Institutional Trust
Entity Central Index Key 0000925723
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2026
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
C000240309  
Shareholder Report [Line Items]  
Fund Name Federated Hermes Institutional High Yield Bond Fund
Class Name Class A Shares
Trading Symbol FIHAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Federated Hermes Institutional High Yield Bond Fund (the "Fund") for the period of November 1, 2025 to April 30, 2026.
Additional Information [Text Block] You can find additional information at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1-800-341-7400, Option 4, or your financial advisor.
Additional Information Phone Number 1-800-341-7400
Additional Information Website FederatedHermes.com/us/FundInformation
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as an annualized percentage of a $10,000 investment
Class A Shares
$38
0.75%
Expenses Paid, Amount $ 38
Expense Ratio, Percent 0.75%
AssetsNet $ 4,835,838,533
Holdings Count | Holding 457
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

  • Net Assets$4,835,838,533
  • Number of Investments457
  • Portfolio Turnover10%
Holdings [Text Block]

Top Index Classifications (% of Net Assets)

Group By Sector Chart
Table Summary
Value
Value
Independent Energy
3.1%
Chemicals
3.8%
Building Materials
4.0%
Automotive
4.2%
Gaming
4.2%
Health Care
4.9%
Cable Satellite
5.4%
Midstream
5.9%
Insurance - P&C
9.0%
Technology
16.3%
Material Fund Change [Text Block]
C000240310  
Shareholder Report [Line Items]  
Fund Name Federated Hermes Institutional High Yield Bond Fund
Class Name Class C Shares
Trading Symbol FIHCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Federated Hermes Institutional High Yield Bond Fund (the "Fund") for the period of November 1, 2025 to April 30, 2026.
Additional Information [Text Block] You can find additional information at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1-800-341-7400, Option 4, or your financial advisor.
Additional Information Phone Number 1-800-341-7400
Additional Information Website FederatedHermes.com/us/FundInformation
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as an annualized percentage of a $10,000 investment
Class C Shares
$76
1.52%
Expenses Paid, Amount $ 76
Expense Ratio, Percent 1.52%
AssetsNet $ 4,835,838,533
Holdings Count | Holding 457
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

  • Net Assets$4,835,838,533
  • Number of Investments457
  • Portfolio Turnover10%
Holdings [Text Block]

Top Index Classifications (% of Net Assets)

Group By Sector Chart
Table Summary
Value
Value
Independent Energy
3.1%
Chemicals
3.8%
Building Materials
4.0%
Automotive
4.2%
Gaming
4.2%
Health Care
4.9%
Cable Satellite
5.4%
Midstream
5.9%
Insurance - P&C
9.0%
Technology
16.3%
Material Fund Change [Text Block]
C000030278  
Shareholder Report [Line Items]  
Fund Name Federated Hermes Institutional High Yield Bond Fund
Class Name Institutional Shares
Trading Symbol FIHBX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Federated Hermes Institutional High Yield Bond Fund (the "Fund") for the period of November 1, 2025 to April 30, 2026.
Additional Information [Text Block] You can find additional information at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1-800-341-7400, Option 4, or your financial advisor.
Additional Information Phone Number 1-800-341-7400
Additional Information Website FederatedHermes.com/us/FundInformation
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as an annualized percentage of a $10,000 investment
Institutional Shares
$25
0.50%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.50%
AssetsNet $ 4,835,838,533
Holdings Count | Holding 457
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

  • Net Assets$4,835,838,533
  • Number of Investments457
  • Portfolio Turnover10%
Holdings [Text Block]

Top Index Classifications (% of Net Assets)

Group By Sector Chart
Table Summary
Value
Value
Independent Energy
3.1%
Chemicals
3.8%
Building Materials
4.0%
Automotive
4.2%
Gaming
4.2%
Health Care
4.9%
Cable Satellite
5.4%
Midstream
5.9%
Insurance - P&C
9.0%
Technology
16.3%
Material Fund Change [Text Block]
C000170849  
Shareholder Report [Line Items]  
Fund Name Federated Hermes Institutional High Yield Bond Fund
Class Name Class R6 Shares
Trading Symbol FIHLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Federated Hermes Institutional High Yield Bond Fund (the "Fund") for the period of November 1, 2025 to April 30, 2026.
Additional Information [Text Block] You can find additional information at FederatedHermes.com/us/FundInformation. You can also request this information by contacting us at 1-800-341-7400, Option 4, or your financial advisor.
Additional Information Phone Number 1-800-341-7400
Additional Information Website FederatedHermes.com/us/FundInformation
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as an annualized percentage of a $10,000 investment
Class R6 Shares
$25
0.49%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.49%
AssetsNet $ 4,835,838,533
Holdings Count | Holding 457
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

  • Net Assets$4,835,838,533
  • Number of Investments457
  • Portfolio Turnover10%
Holdings [Text Block]

Top Index Classifications (% of Net Assets)

Group By Sector Chart
Table Summary
Value
Value
Independent Energy
3.1%
Chemicals
3.8%
Building Materials
4.0%
Automotive
4.2%
Gaming
4.2%
Health Care
4.9%
Cable Satellite
5.4%
Midstream
5.9%
Insurance - P&C
9.0%
Technology
16.3%
Material Fund Change [Text Block]