This semi-annual shareholder report contains important information about Harbor Ares Systematic Convertible Securities Fund (formerly, Harbor Convertible Securities Fund) ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

<span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 16px; margin: 0px; overflow: visible; text-align: left; text-align-last: left; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund</span>

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$33	0.63%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 33

Expense Ratio, Percent

0.63%

AssetsNet

$ 41,931,000

Holdings Count | Holding

146

Advisory Fees Paid, Amount

$ 99,000

InvestmentCompanyPortfolioTurnover

92.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$41,931
Number of Investments	146
Total Net Advisory Fees Paid (in thousands)	$99
Portfolio Turnover Rate	92%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Health Care	1.8%
Materials	2.1%
Energy	3.7%
Consumer Discretionary	6.2%
Communication Services	8.5%
Utilities	9.1%
Industrials	10.7%
Consumer Staples	11.4%
Financials	16.4%
Information Technology	30.1%

C000099979

Shareholder Report [Line Items]

Fund Name

Harbor Ares Systematic Convertible Securities Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HACSX

Annual or Semi-Annual Statement [Text Block]

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$38	0.71%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 38

Expense Ratio, Percent

0.71%

AssetsNet

$ 41,931,000

Holdings Count | Holding

146

Advisory Fees Paid, Amount

$ 99,000

InvestmentCompanyPortfolioTurnover

92.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$41,931
Number of Investments	146
Total Net Advisory Fees Paid (in thousands)	$99
Portfolio Turnover Rate	92%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Health Care	1.8%
Materials	2.1%
Energy	3.7%
Consumer Discretionary	6.2%
Communication Services	8.5%
Utilities	9.1%
Industrials	10.7%
Consumer Staples	11.4%
Financials	16.4%
Information Technology	30.1%

C000099981

Shareholder Report [Line Items]

Fund Name

Harbor Ares Systematic Convertible Securities Fund

Class Name

Investor Class

Trading Symbol

Ticker: HICSX

Annual or Semi-Annual Statement [Text Block]

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$56	1.06%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 56

Expense Ratio, Percent

1.06%

AssetsNet

$ 41,931,000

Holdings Count | Holding

146

Advisory Fees Paid, Amount

$ 99,000

InvestmentCompanyPortfolioTurnover

92.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$41,931
Number of Investments	146
Total Net Advisory Fees Paid (in thousands)	$99
Portfolio Turnover Rate	92%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Health Care	1.8%
Materials	2.1%
Energy	3.7%
Consumer Discretionary	6.2%
Communication Services	8.5%
Utilities	9.1%
Industrials	10.7%
Consumer Staples	11.4%
Financials	16.4%
Information Technology	30.1%

C000166746

Shareholder Report [Line Items]

Fund Name

Harbor Capital Appreciation Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNACX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Capital Appreciation Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$29	0.59%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 29

Expense Ratio, Percent

0.59%

AssetsNet

$ 25,406,575,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 71,275,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$25,406,575
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$71,275
Portfolio Turnover Rate	9%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.5%
Consumer Staples	3.9%
Industrials	4.1%
Financials	5.3%
Health Care	7.8%
Consumer Discretionary	14.8%
Communication Services	16.6%
Information Technology	46.0%

C000001973

Shareholder Report [Line Items]

Fund Name

Harbor Capital Appreciation Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HACAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Capital Appreciation Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$33	0.67%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 33

Expense Ratio, Percent

0.67%

AssetsNet

$ 25,406,575,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 71,275,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$25,406,575
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$71,275
Portfolio Turnover Rate	9%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.5%
Consumer Staples	3.9%
Industrials	4.1%
Financials	5.3%
Health Care	7.8%
Consumer Discretionary	14.8%
Communication Services	16.6%
Information Technology	46.0%

C000001974

Shareholder Report [Line Items]

Fund Name

Harbor Capital Appreciation Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRCAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Capital Appreciation Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$45	0.92%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.92%

AssetsNet

$ 25,406,575,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 71,275,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$25,406,575
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$71,275
Portfolio Turnover Rate	9%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.5%
Consumer Staples	3.9%
Industrials	4.1%
Financials	5.3%
Health Care	7.8%
Consumer Discretionary	14.8%
Communication Services	16.6%
Information Technology	46.0%

C000001975

Shareholder Report [Line Items]

Fund Name

Harbor Capital Appreciation Fund

Class Name

Investor Class

Trading Symbol

Ticker: HCAIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Capital Appreciation Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$50	1.02%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 50

Expense Ratio, Percent

1.02%

AssetsNet

$ 25,406,575,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 71,275,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$25,406,575
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$71,275
Portfolio Turnover Rate	9%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.5%
Consumer Staples	3.9%
Industrials	4.1%
Financials	5.3%
Health Care	7.8%
Consumer Discretionary	14.8%
Communication Services	16.6%
Information Technology	46.0%

C000200769

Shareholder Report [Line Items]

Fund Name

Harbor Core Bond Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HCBRX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Core Bond Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$13	0.26%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 13

Expense Ratio, Percent

0.26%

AssetsNet

$ 1,676,646,000

Holdings Count | Holding

490

Advisory Fees Paid, Amount

$ 1,837,000

InvestmentCompanyPortfolioTurnover

30.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,676,646
Number of Investments	490
Total Net Advisory Fees Paid (in thousands)	$1,837
Portfolio Turnover Rate	30%

Holdings [Text Block]

Investment Allocation (% of Investments)

Table Summary
Value	Value
Municipal Bonds	0.4%
Collateralized Mortgage Obligations	8.5%
Asset-Backed Securities	12.1%
U.S. Government Obligations	24.3%
Mortgage Pass-Through	24.5%
Corporate Bonds & Notes	30.2%

C000200768

Shareholder Report [Line Items]

Fund Name

Harbor Core Bond Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HACBX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Core Bond Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$17	0.34%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 17

Expense Ratio, Percent

0.34%

AssetsNet

$ 1,676,646,000

Holdings Count | Holding

490

Advisory Fees Paid, Amount

$ 1,837,000

InvestmentCompanyPortfolioTurnover

30.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,676,646
Number of Investments	490
Total Net Advisory Fees Paid (in thousands)	$1,837
Portfolio Turnover Rate	30%

Holdings [Text Block]

Investment Allocation (% of Investments)

Table Summary
Value	Value
Municipal Bonds	0.4%
Collateralized Mortgage Obligations	8.5%
Asset-Backed Securities	12.1%
U.S. Government Obligations	24.3%
Mortgage Pass-Through	24.5%
Corporate Bonds & Notes	30.2%

C000200770

Shareholder Report [Line Items]

Fund Name

Harbor Core Plus Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HBFRX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Core Plus Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$15	0.30%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 15

Expense Ratio, Percent

0.30%

AssetsNet

$ 1,260,678,000

Holdings Count | Holding

654

Advisory Fees Paid, Amount

$ 1,564,000

InvestmentCompanyPortfolioTurnover

26.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,260,678
Number of Investments	654
Total Net Advisory Fees Paid (in thousands)	$1,564
Portfolio Turnover Rate	26%

Holdings [Text Block]

Investment Allocation (% of Investments)

Table Summary
Value	Value
Collateralized Mortgage Obligations	11.5%
Asset-Backed Securities	11.7%
U.S. Government Obligations	20.6%
Mortgage Pass-Through	26.0%
Corporate Bonds & Notes	30.2%

C000001976

Shareholder Report [Line Items]

Fund Name

Harbor Core Plus Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HABDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Core Plus Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$19	0.38%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 19

Expense Ratio, Percent

0.38%

AssetsNet

$ 1,260,678,000

Holdings Count | Holding

654

Advisory Fees Paid, Amount

$ 1,564,000

InvestmentCompanyPortfolioTurnover

26.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,260,678
Number of Investments	654
Total Net Advisory Fees Paid (in thousands)	$1,564
Portfolio Turnover Rate	26%

Holdings [Text Block]

Investment Allocation (% of Investments)

Table Summary
Value	Value
Collateralized Mortgage Obligations	11.5%
Asset-Backed Securities	11.7%
U.S. Government Obligations	20.6%
Mortgage Pass-Through	26.0%
Corporate Bonds & Notes	30.2%

C000001977

Shareholder Report [Line Items]

Fund Name

Harbor Core Plus Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRBDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Core Plus Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$31	0.63%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 31

Expense Ratio, Percent

0.63%

AssetsNet

$ 1,260,678,000

Holdings Count | Holding

654

Advisory Fees Paid, Amount

$ 1,564,000

InvestmentCompanyPortfolioTurnover

26.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,260,678
Number of Investments	654
Total Net Advisory Fees Paid (in thousands)	$1,564
Portfolio Turnover Rate	26%

Holdings [Text Block]

Investment Allocation (% of Investments)

Table Summary
Value	Value
Collateralized Mortgage Obligations	11.5%
Asset-Backed Securities	11.7%
U.S. Government Obligations	20.6%
Mortgage Pass-Through	26.0%
Corporate Bonds & Notes	30.2%

C000166759

Shareholder Report [Line Items]

Fund Name

Harbor Diversified International All Cap Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNIDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Diversified International All Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$39	0.75%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 39

Expense Ratio, Percent

0.75%

AssetsNet

$ 799,998,000

Holdings Count | Holding

245

Advisory Fees Paid, Amount

$ 2,882,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$799,998
Number of Investments (includes derivatives)	245
Total Net Advisory Fees Paid (in thousands)	$2,882
Portfolio Turnover Rate	8%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.7%
Africa	3.9%
Latin America	4.0%
North America	11.3%
Pacific Basin	36.9%
Europe	40.2%

C000161865

Shareholder Report [Line Items]

Fund Name

Harbor Diversified International All Cap Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAIDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Diversified International All Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$44	0.83%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 44

Expense Ratio, Percent

0.83%

AssetsNet

$ 799,998,000

Holdings Count | Holding

245

Advisory Fees Paid, Amount

$ 2,882,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$799,998
Number of Investments (includes derivatives)	245
Total Net Advisory Fees Paid (in thousands)	$2,882
Portfolio Turnover Rate	8%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.7%
Africa	3.9%
Latin America	4.0%
North America	11.3%
Pacific Basin	36.9%
Europe	40.2%

C000161866

Shareholder Report [Line Items]

Fund Name

Harbor Diversified International All Cap Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRIDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Diversified International All Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$57	1.08%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 57

Expense Ratio, Percent

1.08%

AssetsNet

$ 799,998,000

Holdings Count | Holding

245

Advisory Fees Paid, Amount

$ 2,882,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$799,998
Number of Investments (includes derivatives)	245
Total Net Advisory Fees Paid (in thousands)	$2,882
Portfolio Turnover Rate	8%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.7%
Africa	3.9%
Latin America	4.0%
North America	11.3%
Pacific Basin	36.9%
Europe	40.2%

C000161867

Shareholder Report [Line Items]

Fund Name

Harbor Diversified International All Cap Fund

Class Name

Investor Class

Trading Symbol

Ticker: HIIDX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Diversified International All Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$62	1.18%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 62

Expense Ratio, Percent

1.18%

AssetsNet

$ 799,998,000

Holdings Count | Holding

245

Advisory Fees Paid, Amount

$ 2,882,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$799,998
Number of Investments (includes derivatives)	245
Total Net Advisory Fees Paid (in thousands)	$2,882
Portfolio Turnover Rate	8%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.7%
Africa	3.9%
Latin America	4.0%
North America	11.3%
Pacific Basin	36.9%
Europe	40.2%

C000166752

Shareholder Report [Line Items]

Fund Name

Harbor International Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNINX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$37	0.72%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 37

Expense Ratio, Percent

0.72%

AssetsNet

$ 3,775,973,000

Holdings Count | Holding

222

Advisory Fees Paid, Amount

$ 14,071,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$3,775,973
Number of Investments	222
Total Net Advisory Fees Paid (in thousands)	$14,071
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.9%
Pacific Basin	34.6%
Europe	61.5%

C000001997

Shareholder Report [Line Items]

Fund Name

Harbor International Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAINX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$41	0.80%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.80%

AssetsNet

$ 3,775,973,000

Holdings Count | Holding

222

Advisory Fees Paid, Amount

$ 14,071,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$3,775,973
Number of Investments	222
Total Net Advisory Fees Paid (in thousands)	$14,071
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.9%
Pacific Basin	34.6%
Europe	61.5%

C000001998

Shareholder Report [Line Items]

Fund Name

Harbor International Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRINX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$54	1.05%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 54

Expense Ratio, Percent

1.05%

AssetsNet

$ 3,775,973,000

Holdings Count | Holding

222

Advisory Fees Paid, Amount

$ 14,071,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$3,775,973
Number of Investments	222
Total Net Advisory Fees Paid (in thousands)	$14,071
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.9%
Pacific Basin	34.6%
Europe	61.5%

C000001999

Shareholder Report [Line Items]

Fund Name

Harbor International Fund

Class Name

Investor Class

Trading Symbol

Ticker: HIINX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$59	1.15%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.15%

AssetsNet

$ 3,775,973,000

Holdings Count | Holding

222

Advisory Fees Paid, Amount

$ 14,071,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$3,775,973
Number of Investments	222
Total Net Advisory Fees Paid (in thousands)	$14,071
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	3.9%
Pacific Basin	34.6%
Europe	61.5%

C000248152

Shareholder Report [Line Items]

Fund Name

Harbor International Compounders Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNICX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Compounders Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$28	0.55%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 28

Expense Ratio, Percent

0.55%

AssetsNet

$ 45,965,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 122,000

InvestmentCompanyPortfolioTurnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$45,965
Number of Investments	31
Total Net Advisory Fees Paid (in thousands)	$122
Portfolio Turnover Rate	13%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
South Asia	3.8%
Latin America	5.0%
North America	6.7%
Pacific Basin	29.7%
Europe	54.8%

C000248153

Shareholder Report [Line Items]

Fund Name

Harbor International Compounders Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HSICX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Compounders Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$32	0.63%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 32

Expense Ratio, Percent

0.63%

AssetsNet

$ 45,965,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 122,000

InvestmentCompanyPortfolioTurnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$45,965
Number of Investments	31
Total Net Advisory Fees Paid (in thousands)	$122
Portfolio Turnover Rate	13%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
South Asia	3.8%
Latin America	5.0%
North America	6.7%
Pacific Basin	29.7%
Europe	54.8%

C000210023

Shareholder Report [Line Items]

Fund Name

Harbor International Core Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HAORX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Core Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$41	0.77%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.77%

AssetsNet

$ 1,740,173,000

Holdings Count | Holding

753

Advisory Fees Paid, Amount

$ 5,085,000

InvestmentCompanyPortfolioTurnover

49.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,740,173
Number of Investments	753
Total Net Advisory Fees Paid (in thousands)	$5,085
Portfolio Turnover Rate	49%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	1.3%
Middle East/Central Asia	2.1%
North America	15.2%
Pacific Basin	31.2%
Europe	50.2%

C000210022

Shareholder Report [Line Items]

Fund Name

Harbor International Core Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAOSX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Core Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$45	0.85%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.85%

AssetsNet

$ 1,740,173,000

Holdings Count | Holding

753

Advisory Fees Paid, Amount

$ 5,085,000

InvestmentCompanyPortfolioTurnover

49.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,740,173
Number of Investments	753
Total Net Advisory Fees Paid (in thousands)	$5,085
Portfolio Turnover Rate	49%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	1.3%
Middle East/Central Asia	2.1%
North America	15.2%
Pacific Basin	31.2%
Europe	50.2%

C000210024

Shareholder Report [Line Items]

Fund Name

Harbor International Core Fund

Class Name

Investor Class

Trading Symbol

Ticker: HAONX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Core Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$64	1.20%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 64

Expense Ratio, Percent

1.20%

AssetsNet

$ 1,740,173,000

Holdings Count | Holding

753

Advisory Fees Paid, Amount

$ 5,085,000

InvestmentCompanyPortfolioTurnover

49.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,740,173
Number of Investments	753
Total Net Advisory Fees Paid (in thousands)	$5,085
Portfolio Turnover Rate	49%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
Other	1.3%
Middle East/Central Asia	2.1%
North America	15.2%
Pacific Basin	31.2%
Europe	50.2%

C000165338

Shareholder Report [Line Items]

Fund Name

Harbor International Small Cap Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNISX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Small Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$43	0.82%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 43

Expense Ratio, Percent

0.82%

AssetsNet

$ 187,352,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 758,000

InvestmentCompanyPortfolioTurnover

16.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$187,352
Number of Investments	65
Total Net Advisory Fees Paid (in thousands)	$758
Portfolio Turnover Rate	16%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
North America	2.9%
Pacific Basin	41.5%
Europe	55.6%

C000165335

Shareholder Report [Line Items]

Fund Name

Harbor International Small Cap Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAISX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Small Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$48	0.90%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 48

Expense Ratio, Percent

0.90%

AssetsNet

$ 187,352,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 758,000

InvestmentCompanyPortfolioTurnover

16.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$187,352
Number of Investments	65
Total Net Advisory Fees Paid (in thousands)	$758
Portfolio Turnover Rate	16%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
North America	2.9%
Pacific Basin	41.5%
Europe	55.6%

C000165337

Shareholder Report [Line Items]

Fund Name

Harbor International Small Cap Fund

Class Name

Investor Class

Trading Symbol

Ticker: HIISX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor International Small Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$66	1.25%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 66

Expense Ratio, Percent

1.25%

AssetsNet

$ 187,352,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 758,000

InvestmentCompanyPortfolioTurnover

16.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$187,352
Number of Investments	65
Total Net Advisory Fees Paid (in thousands)	$758
Portfolio Turnover Rate	16%

Holdings [Text Block]

Region Breakdown (% of Investments)

Table Summary
Value	Value
North America	2.9%
Pacific Basin	41.5%
Europe	55.6%

C000166749

Shareholder Report [Line Items]

Fund Name

Harbor Large Cap Value Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNLVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Large Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$31	0.61%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 31

Expense Ratio, Percent

0.61%

AssetsNet

$ 1,037,257,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 3,420,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,037,257
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$3,420
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Real Estate	1.4%
Energy	4.7%
Consumer Staples	5.5%
Consumer Discretionary	5.9%
Utilities	6.3%
Communication Services	6.9%
Health Care	9.2%
Industrials	10.6%
Materials	12.5%
Information Technology	17.0%
Financials	20.0%

C000001988

Shareholder Report [Line Items]

Fund Name

Harbor Large Cap Value Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAVLX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Large Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$35	0.69%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 35

Expense Ratio, Percent

0.69%

AssetsNet

$ 1,037,257,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 3,420,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,037,257
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$3,420
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Real Estate	1.4%
Energy	4.7%
Consumer Staples	5.5%
Consumer Discretionary	5.9%
Utilities	6.3%
Communication Services	6.9%
Health Care	9.2%
Industrials	10.6%
Materials	12.5%
Information Technology	17.0%
Financials	20.0%

C000001990

Shareholder Report [Line Items]

Fund Name

Harbor Large Cap Value Fund

Class Name

Investor Class

Trading Symbol

Ticker: HILVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Large Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$53	1.04%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 53

Expense Ratio, Percent

1.04%

AssetsNet

$ 1,037,257,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 3,420,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$1,037,257
Number of Investments	45
Total Net Advisory Fees Paid (in thousands)	$3,420
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Real Estate	1.4%
Energy	4.7%
Consumer Staples	5.5%
Consumer Discretionary	5.9%
Utilities	6.3%
Communication Services	6.9%
Health Care	9.2%
Industrials	10.6%
Materials	12.5%
Information Technology	17.0%
Financials	20.0%

C000215757

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HMCRX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$43	0.80%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 43

Expense Ratio, Percent

0.80%

AssetsNet

$ 207,646,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 699,000

InvestmentCompanyPortfolioTurnover

3.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$207,646
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$699
Portfolio Turnover Rate	3%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Consumer Staples	1.1%
Utilities	1.7%
Energy	4.4%
Real Estate	5.2%
Materials	6.3%
Consumer Discretionary	8.6%
Health Care	9.8%
Financials	15.6%
Information Technology	17.5%
Industrials	29.8%

C000215758

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HMCLX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$47	0.88%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 47

Expense Ratio, Percent

0.88%

AssetsNet

$ 207,646,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 699,000

InvestmentCompanyPortfolioTurnover

3.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$207,646
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$699
Portfolio Turnover Rate	3%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Consumer Staples	1.1%
Utilities	1.7%
Energy	4.4%
Real Estate	5.2%
Materials	6.3%
Consumer Discretionary	8.6%
Health Care	9.8%
Financials	15.6%
Information Technology	17.5%
Industrials	29.8%

C000215756

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Fund

Class Name

Investor Class

Trading Symbol

Ticker: HMCNX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$66	1.23%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 66

Expense Ratio, Percent

1.23%

AssetsNet

$ 207,646,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 699,000

InvestmentCompanyPortfolioTurnover

3.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$207,646
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$699
Portfolio Turnover Rate	3%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Consumer Staples	1.1%
Utilities	1.7%
Energy	4.4%
Real Estate	5.2%
Materials	6.3%
Consumer Discretionary	8.6%
Health Care	9.8%
Financials	15.6%
Information Technology	17.5%
Industrials	29.8%

C000166750

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Value Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNMVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$42	0.77%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.77%

AssetsNet

$ 425,460,000

Holdings Count | Holding

181

Advisory Fees Paid, Amount

$ 1,458,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$425,460
Number of Investments	181
Total Net Advisory Fees Paid (in thousands)	$1,458
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Communication Services	2.9%
Utilities	3.1%
Materials	4.5%
Real Estate	5.3%
Consumer Staples	7.7%
Energy	8.4%
Health Care	9.2%
Information Technology	12.1%
Consumer Discretionary	12.3%
Industrials	14.4%
Financials	20.1%

C000001991

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Value Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HAMVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$46	0.85%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 46

Expense Ratio, Percent

0.85%

AssetsNet

$ 425,460,000

Holdings Count | Holding

181

Advisory Fees Paid, Amount

$ 1,458,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$425,460
Number of Investments	181
Total Net Advisory Fees Paid (in thousands)	$1,458
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Communication Services	2.9%
Utilities	3.1%
Materials	4.5%
Real Estate	5.3%
Consumer Staples	7.7%
Energy	8.4%
Health Care	9.2%
Information Technology	12.1%
Consumer Discretionary	12.3%
Industrials	14.4%
Financials	20.1%

C000001992

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Value Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRMVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$60	1.10%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 60

Expense Ratio, Percent

1.10%

AssetsNet

$ 425,460,000

Holdings Count | Holding

181

Advisory Fees Paid, Amount

$ 1,458,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$425,460
Number of Investments	181
Total Net Advisory Fees Paid (in thousands)	$1,458
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Communication Services	2.9%
Utilities	3.1%
Materials	4.5%
Real Estate	5.3%
Consumer Staples	7.7%
Energy	8.4%
Health Care	9.2%
Information Technology	12.1%
Consumer Discretionary	12.3%
Industrials	14.4%
Financials	20.1%

C000001993

Shareholder Report [Line Items]

Fund Name

Harbor Mid Cap Value Fund

Class Name

Investor Class

Trading Symbol

Ticker: HIMVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Mid Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$65	1.20%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 65

Expense Ratio, Percent

1.20%

AssetsNet

$ 425,460,000

Holdings Count | Holding

181

Advisory Fees Paid, Amount

$ 1,458,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$425,460
Number of Investments	181
Total Net Advisory Fees Paid (in thousands)	$1,458
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Communication Services	2.9%
Utilities	3.1%
Materials	4.5%
Real Estate	5.3%
Consumer Staples	7.7%
Energy	8.4%
Health Care	9.2%
Information Technology	12.1%
Consumer Discretionary	12.3%
Industrials	14.4%
Financials	20.1%

C000166748

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Growth Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNSGX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Growth Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$42	0.79%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.79%

AssetsNet

$ 2,588,613,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,415,000

InvestmentCompanyPortfolioTurnover

46.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,588,613
Number of Investments	77
Total Net Advisory Fees Paid (in thousands)	$8,415
Portfolio Turnover Rate	46%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Materials	1.5%
Communication Services	1.9%
Energy	2.4%
Consumer Staples	2.4%
Consumer Discretionary	6.8%
Financials	10.3%
Health Care	20.3%
Information Technology	20.8%
Industrials	33.6%

C000001985

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Growth Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HASGX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Growth Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$46	0.87%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 46

Expense Ratio, Percent

0.87%

AssetsNet

$ 2,588,613,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,415,000

InvestmentCompanyPortfolioTurnover

46.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,588,613
Number of Investments	77
Total Net Advisory Fees Paid (in thousands)	$8,415
Portfolio Turnover Rate	46%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Materials	1.5%
Communication Services	1.9%
Energy	2.4%
Consumer Staples	2.4%
Consumer Discretionary	6.8%
Financials	10.3%
Health Care	20.3%
Information Technology	20.8%
Industrials	33.6%

C000001987

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Growth Fund

Class Name

Investor Class

Trading Symbol

Ticker: HISGX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Growth Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$64	1.22%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 64

Expense Ratio, Percent

1.22%

AssetsNet

$ 2,588,613,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,415,000

InvestmentCompanyPortfolioTurnover

46.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,588,613
Number of Investments	77
Total Net Advisory Fees Paid (in thousands)	$8,415
Portfolio Turnover Rate	46%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Materials	1.5%
Communication Services	1.9%
Energy	2.4%
Consumer Staples	2.4%
Consumer Discretionary	6.8%
Financials	10.3%
Health Care	20.3%
Information Technology	20.8%
Industrials	33.6%

C000166751

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Value Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNVRX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$45	0.80%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.80%

AssetsNet

$ 2,532,119,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,294,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,532,119
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$8,294
Portfolio Turnover Rate	7%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.6%
Health Care	1.9%
Consumer Staples	2.6%
Materials	3.0%
Real Estate	3.5%
Consumer Discretionary	4.8%
Energy	7.1%
Financials	22.8%
Information Technology	24.5%
Industrials	28.2%

C000001994

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Value Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HASCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$50	0.88%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 50

Expense Ratio, Percent

0.88%

AssetsNet

$ 2,532,119,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,294,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,532,119
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$8,294
Portfolio Turnover Rate	7%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.6%
Health Care	1.9%
Consumer Staples	2.6%
Materials	3.0%
Real Estate	3.5%
Consumer Discretionary	4.8%
Energy	7.1%
Financials	22.8%
Information Technology	24.5%
Industrials	28.2%

C000001995

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Value Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HSVRX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$64	1.13%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 64

Expense Ratio, Percent

1.13%

AssetsNet

$ 2,532,119,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,294,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,532,119
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$8,294
Portfolio Turnover Rate	7%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.6%
Health Care	1.9%
Consumer Staples	2.6%
Materials	3.0%
Real Estate	3.5%
Consumer Discretionary	4.8%
Energy	7.1%
Financials	22.8%
Information Technology	24.5%
Industrials	28.2%

C000001996

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Value Fund

Class Name

Investor Class

Trading Symbol

Ticker: HISVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Small Cap Value Fund ("Fund") for the period of November 1, 2025 to April 30, 2026.

Additional Information [Text Block]

You can find additional information about the Fund at www.harborcapital.com/documents/fund. You can also request this information by contacting us at 800-422-1050.

Additional Information Phone Number

800-422-1050

Additional Information Website

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$69	1.22%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 69

Expense Ratio, Percent

1.22%

AssetsNet

$ 2,532,119,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,294,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics as of April 30, 2026

Table Summary
Total Net Assets (in thousands)	$2,532,119
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$8,294
Portfolio Turnover Rate	7%

Holdings [Text Block]

Sector Allocation (% of Investments)

Table Summary
Value	Value
Utilities	1.6%
Health Care	1.9%
Consumer Staples	2.6%
Materials	3.0%
Real Estate	3.5%
Consumer Discretionary	4.8%
Energy	7.1%
Financials	22.8%
Information Technology	24.5%
Industrials	28.2%