This semi-annual shareholder report contains important information about Harbor Capital Appreciation Fund ("Fund") for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

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

$ 25,029,668,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 76,431,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,029,668
Number of Investments	54
Total Net Advisory Fees Paid (in thousands)	$76,431
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	34.1%
Communication Services	18.8%
Consumer Discretionary	17.1%
Health Care	10.7%
Financials	8.6%
Industrials	5.6%
Consumer Staples	4.2%
Utilities	0.9%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 25,029,668,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 76,431,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,029,668
Number of Investments	54
Total Net Advisory Fees Paid (in thousands)	$76,431
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	34.1%
Communication Services	18.8%
Consumer Discretionary	17.1%
Health Care	10.7%
Financials	8.6%
Industrials	5.6%
Consumer Staples	4.2%
Utilities	0.9%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 25,029,668,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 76,431,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,029,668
Number of Investments	54
Total Net Advisory Fees Paid (in thousands)	$76,431
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	34.1%
Communication Services	18.8%
Consumer Discretionary	17.1%
Health Care	10.7%
Financials	8.6%
Industrials	5.6%
Consumer Staples	4.2%
Utilities	0.9%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 25,029,668,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 76,431,000

InvestmentCompanyPortfolioTurnover

15.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,029,668
Number of Investments	54
Total Net Advisory Fees Paid (in thousands)	$76,431
Portfolio Turnover Rate	15%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	34.1%
Communication Services	18.8%
Consumer Discretionary	17.1%
Health Care	10.7%
Financials	8.6%
Industrials	5.6%
Consumer Staples	4.2%
Utilities	0.9%

C000166756

Shareholder Report [Line Items]

Fund Name

Harbor Convertible Securities Fund

Class Name

Retirement Class

Trading Symbol

Ticker: HNCVX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Convertible Securities Fund ("Fund") for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 32

Expense Ratio, Percent

0.63%

AssetsNet

$ 25,483,000

Holdings Count | Holding

145

Advisory Fees Paid, Amount

$ 64,000

InvestmentCompanyPortfolioTurnover

71.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,483
Number of Investments	145
Total Net Advisory Fees Paid (in thousands)	$64
Portfolio Turnover Rate	71%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	25.6%
Financials	16.2%
Industrials	11.0%
Consumer Discretionary	10.6%
Communication Services	9.2%
Consumer Staples	8.5%
Utilities	7.5%
Health Care	7.4%
Energy	1.6%
Materials	1.2%
Real Estate	1.2%

C000099979

Shareholder Report [Line Items]

Fund Name

Harbor Convertible Securities Fund

Class Name

Institutional Class

Trading Symbol

Ticker: HACSX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Convertible Securities Fund ("Fund") for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$36	0.71%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 36

Expense Ratio, Percent

0.71%

AssetsNet

$ 25,483,000

Holdings Count | Holding

145

Advisory Fees Paid, Amount

$ 64,000

InvestmentCompanyPortfolioTurnover

71.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,483
Number of Investments	145
Total Net Advisory Fees Paid (in thousands)	$64
Portfolio Turnover Rate	71%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	25.6%
Financials	16.2%
Industrials	11.0%
Consumer Discretionary	10.6%
Communication Services	9.2%
Consumer Staples	8.5%
Utilities	7.5%
Health Care	7.4%
Energy	1.6%
Materials	1.2%
Real Estate	1.2%

C000099980

Shareholder Report [Line Items]

Fund Name

Harbor Convertible Securities Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRCSX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Convertible Securities Fund ("Fund") for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$48	0.96%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 48

Expense Ratio, Percent

0.96%

AssetsNet

$ 25,483,000

Holdings Count | Holding

145

Advisory Fees Paid, Amount

$ 64,000

InvestmentCompanyPortfolioTurnover

71.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,483
Number of Investments	145
Total Net Advisory Fees Paid (in thousands)	$64
Portfolio Turnover Rate	71%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	25.6%
Financials	16.2%
Industrials	11.0%
Consumer Discretionary	10.6%
Communication Services	9.2%
Consumer Staples	8.5%
Utilities	7.5%
Health Care	7.4%
Energy	1.6%
Materials	1.2%
Real Estate	1.2%

C000099981

Shareholder Report [Line Items]

Fund Name

Harbor Convertible Securities Fund

Class Name

Investor Class

Trading Symbol

Ticker: HICSX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about Harbor Convertible Securities Fund ("Fund") for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$54	1.07%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 54

Expense Ratio, Percent

1.07%

AssetsNet

$ 25,483,000

Holdings Count | Holding

145

Advisory Fees Paid, Amount

$ 64,000

InvestmentCompanyPortfolioTurnover

71.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$25,483
Number of Investments	145
Total Net Advisory Fees Paid (in thousands)	$64
Portfolio Turnover Rate	71%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Information Technology	25.6%
Financials	16.2%
Industrials	11.0%
Consumer Discretionary	10.6%
Communication Services	9.2%
Consumer Staples	8.5%
Utilities	7.5%
Health Care	7.4%
Energy	1.6%
Materials	1.2%
Real Estate	1.2%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 1,404,331,000

Holdings Count | Holding

507

Advisory Fees Paid, Amount

$ 1,538,000

InvestmentCompanyPortfolioTurnover

23.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,404,331
Number of Investments	507
Total Net Advisory Fees Paid (in thousands)	$1,538
Portfolio Turnover Rate	23%

Holdings [Text Block]

Investment Allocation (% of Investments)

Value	Value
Corporate Bonds & Notes	31.8%
Mortgage Pass-Through	26.3%
U.S. Government Obligations	21.3%
Asset-Backed Securities	13.0%
Collateralized Mortgage Obligations	7.0%
Municipal Bonds	0.6%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 1,404,331,000

Holdings Count | Holding

507

Advisory Fees Paid, Amount

$ 1,538,000

InvestmentCompanyPortfolioTurnover

23.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,404,331
Number of Investments	507
Total Net Advisory Fees Paid (in thousands)	$1,538
Portfolio Turnover Rate	23%

Holdings [Text Block]

Investment Allocation (% of Investments)

Value	Value
Corporate Bonds & Notes	31.8%
Mortgage Pass-Through	26.3%
U.S. Government Obligations	21.3%
Asset-Backed Securities	13.0%
Collateralized Mortgage Obligations	7.0%
Municipal Bonds	0.6%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 1,188,637,000

Holdings Count | Holding

685

Advisory Fees Paid, Amount

$ 1,447,000

InvestmentCompanyPortfolioTurnover

22.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,188,637
Number of Investments	685
Total Net Advisory Fees Paid (in thousands)	$1,447
Portfolio Turnover Rate	22%

Holdings [Text Block]

Investment Allocation (% of Investments)

Value	Value
Corporate Bonds & Notes	30.5%
Mortgage Pass-Through	27.3%
U.S. Government Obligations	19.6%
Asset-Backed Securities	12.2%
Collateralized Mortgage Obligations	10.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

$ 1,188,637,000

Holdings Count | Holding

685

Advisory Fees Paid, Amount

$ 1,447,000

InvestmentCompanyPortfolioTurnover

22.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,188,637
Number of Investments	685
Total Net Advisory Fees Paid (in thousands)	$1,447
Portfolio Turnover Rate	22%

Holdings [Text Block]

Investment Allocation (% of Investments)

Value	Value
Corporate Bonds & Notes	30.5%
Mortgage Pass-Through	27.3%
U.S. Government Obligations	19.6%
Asset-Backed Securities	12.2%
Collateralized Mortgage Obligations	10.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 32

Expense Ratio, Percent

0.63%

AssetsNet

$ 1,188,637,000

Holdings Count | Holding

685

Advisory Fees Paid, Amount

$ 1,447,000

InvestmentCompanyPortfolioTurnover

22.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,188,637
Number of Investments	685
Total Net Advisory Fees Paid (in thousands)	$1,447
Portfolio Turnover Rate	22%

Holdings [Text Block]

Investment Allocation (% of Investments)

Value	Value
Corporate Bonds & Notes	30.5%
Mortgage Pass-Through	27.3%
U.S. Government Obligations	19.6%
Asset-Backed Securities	12.2%
Collateralized Mortgage Obligations	10.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$37	0.73%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 37

Expense Ratio, Percent

0.73%

AssetsNet

$ 775,312,000

Holdings Count | Holding

247

Advisory Fees Paid, Amount

$ 3,177,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$775,312
Number of Investments (excludes derivatives)	247
Total Net Advisory Fees Paid (in thousands)	$3,177
Portfolio Turnover Rate	9%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	42.1%
Pacific Basin	33.1%
North America	10.3%
Latin America	5.8%
South Asia	3.6%
Africa	3.6%
Middle East/Central Asia	1.5%

Country Breakdown (% of Investments)

United Kingdom	19.2%
Japan	17.6%
Canada	8.2%
France	4.3%
Taiwan	4.0%
China	3.9%
India	3.6%
South Africa	3.6%
Denmark	3.3%
Hong Kong	3.1%
Australia	2.8%
Germany	2.8%
Mexico	2.6%
Other	21.0%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$41	0.81%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.81%

AssetsNet

$ 775,312,000

Holdings Count | Holding

247

Advisory Fees Paid, Amount

$ 3,177,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$775,312
Number of Investments (excludes derivatives)	247
Total Net Advisory Fees Paid (in thousands)	$3,177
Portfolio Turnover Rate	9%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	42.1%
Pacific Basin	33.1%
North America	10.3%
Latin America	5.8%
South Asia	3.6%
Africa	3.6%
Middle East/Central Asia	1.5%

Country Breakdown (% of Investments)

United Kingdom	19.2%
Japan	17.6%
Canada	8.2%
France	4.3%
Taiwan	4.0%
China	3.9%
India	3.6%
South Africa	3.6%
Denmark	3.3%
Hong Kong	3.1%
Australia	2.8%
Germany	2.8%
Mexico	2.6%
Other	21.0%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$54	1.06%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 54

Expense Ratio, Percent

1.06%

AssetsNet

$ 775,312,000

Holdings Count | Holding

247

Advisory Fees Paid, Amount

$ 3,177,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$775,312
Number of Investments (excludes derivatives)	247
Total Net Advisory Fees Paid (in thousands)	$3,177
Portfolio Turnover Rate	9%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	42.1%
Pacific Basin	33.1%
North America	10.3%
Latin America	5.8%
South Asia	3.6%
Africa	3.6%
Middle East/Central Asia	1.5%

Country Breakdown (% of Investments)

United Kingdom	19.2%
Japan	17.6%
Canada	8.2%
France	4.3%
Taiwan	4.0%
China	3.9%
India	3.6%
South Africa	3.6%
Denmark	3.3%
Hong Kong	3.1%
Australia	2.8%
Germany	2.8%
Mexico	2.6%
Other	21.0%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$60	1.17%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 60

Expense Ratio, Percent

1.17%

AssetsNet

$ 775,312,000

Holdings Count | Holding

247

Advisory Fees Paid, Amount

$ 3,177,000

InvestmentCompanyPortfolioTurnover

9.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$775,312
Number of Investments (excludes derivatives)	247
Total Net Advisory Fees Paid (in thousands)	$3,177
Portfolio Turnover Rate	9%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	42.1%
Pacific Basin	33.1%
North America	10.3%
Latin America	5.8%
South Asia	3.6%
Africa	3.6%
Middle East/Central Asia	1.5%

Country Breakdown (% of Investments)

United Kingdom	19.2%
Japan	17.6%
Canada	8.2%
France	4.3%
Taiwan	4.0%
China	3.9%
India	3.6%
South Africa	3.6%
Denmark	3.3%
Hong Kong	3.1%
Australia	2.8%
Germany	2.8%
Mexico	2.6%
Other	21.0%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$36	0.70%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 36

Expense Ratio, Percent

0.70%

AssetsNet

$ 3,472,455,000

Holdings Count | Holding

227

Advisory Fees Paid, Amount

$ 12,608,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$3,472,455
Number of Investments	227
Total Net Advisory Fees Paid (in thousands)	$12,608
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	58.6%
Pacific Basin	35.0%
North America	4.0%
Latin America	0.9%
Africa	0.7%
South Asia	0.6%
Middle East/Central Asia	0.2%

Country Breakdown (% of Investments)

United Kingdom	27.8%
Japan	25.4%
France	5.0%
Denmark	4.8%
Australia	4.0%
Germany	4.0%
United States	3.9%
Hong Kong	2.9%
Switzerland	2.9%
Other	19.3%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$40	0.78%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.78%

AssetsNet

$ 3,472,455,000

Holdings Count | Holding

227

Advisory Fees Paid, Amount

$ 12,608,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$3,472,455
Number of Investments	227
Total Net Advisory Fees Paid (in thousands)	$12,608
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	58.6%
Pacific Basin	35.0%
North America	4.0%
Latin America	0.9%
Africa	0.7%
South Asia	0.6%
Middle East/Central Asia	0.2%

Country Breakdown (% of Investments)

United Kingdom	27.8%
Japan	25.4%
France	5.0%
Denmark	4.8%
Australia	4.0%
Germany	4.0%
United States	3.9%
Hong Kong	2.9%
Switzerland	2.9%
Other	19.3%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$53	1.03%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 53

Expense Ratio, Percent

1.03%

AssetsNet

$ 3,472,455,000

Holdings Count | Holding

227

Advisory Fees Paid, Amount

$ 12,608,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$3,472,455
Number of Investments	227
Total Net Advisory Fees Paid (in thousands)	$12,608
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	58.6%
Pacific Basin	35.0%
North America	4.0%
Latin America	0.9%
Africa	0.7%
South Asia	0.6%
Middle East/Central Asia	0.2%

Country Breakdown (% of Investments)

United Kingdom	27.8%
Japan	25.4%
France	5.0%
Denmark	4.8%
Australia	4.0%
Germany	4.0%
United States	3.9%
Hong Kong	2.9%
Switzerland	2.9%
Other	19.3%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$59	1.14%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.14%

AssetsNet

$ 3,472,455,000

Holdings Count | Holding

227

Advisory Fees Paid, Amount

$ 12,608,000

InvestmentCompanyPortfolioTurnover

7.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$3,472,455
Number of Investments	227
Total Net Advisory Fees Paid (in thousands)	$12,608
Portfolio Turnover Rate	7%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	58.6%
Pacific Basin	35.0%
North America	4.0%
Latin America	0.9%
Africa	0.7%
South Asia	0.6%
Middle East/Central Asia	0.2%

Country Breakdown (% of Investments)

United Kingdom	27.8%
Japan	25.4%
France	5.0%
Denmark	4.8%
Australia	4.0%
Germany	4.0%
United States	3.9%
Hong Kong	2.9%
Switzerland	2.9%
Other	19.3%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

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

$ 45,724,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 69,000

InvestmentCompanyPortfolioTurnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$45,724
Number of Investments	29
Total Net Advisory Fees Paid (in thousands)	$69
Portfolio Turnover Rate	5%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	53.2%
Pacific Basin	24.8%
North America	15.9%
South Asia	6.1%

Country Breakdown (% of Investments)

United Kingdom	15.9%
United States	15.9%
Germany	15.1%
Japan	14.9%
France	8.3%
Sweden	8.1%
India	6.1%
Taiwan	4.2%
Denmark	3.3%
Hong Kong	3.2%
Netherlands	2.5%
Indonesia	2.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

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

$ 45,724,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 69,000

InvestmentCompanyPortfolioTurnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$45,724
Number of Investments	29
Total Net Advisory Fees Paid (in thousands)	$69
Portfolio Turnover Rate	5%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	53.2%
Pacific Basin	24.8%
North America	15.9%
South Asia	6.1%

Country Breakdown (% of Investments)

United Kingdom	15.9%
United States	15.9%
Germany	15.1%
Japan	14.9%
France	8.3%
Sweden	8.1%
India	6.1%
Taiwan	4.2%
Denmark	3.3%
Hong Kong	3.2%
Netherlands	2.5%
Indonesia	2.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$40	0.77%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.77%

AssetsNet

$ 453,510,000

Holdings Count | Holding

466

Advisory Fees Paid, Amount

$ 1,166,000

InvestmentCompanyPortfolioTurnover

59.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$453,510
Number of Investments	466
Total Net Advisory Fees Paid (in thousands)	$1,166
Portfolio Turnover Rate	59%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	54.1%
Pacific Basin	31.1%
North America	10.9%
Middle East/Central Asia	3.2%
South Asia	0.4%
Africa	0.2%
Latin America	0.1%

Country Breakdown (% of Investments)

Japan	19.0%
Germany	11.2%
United States	10.7%
France	9.0%
United Kingdom	8.1%
Netherlands	6.9%
Australia	6.2%
Switzerland	4.7%
Spain	3.5%
Singapore	2.2%
Other	18.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

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

$ 453,510,000

Holdings Count | Holding

466

Advisory Fees Paid, Amount

$ 1,166,000

InvestmentCompanyPortfolioTurnover

59.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$453,510
Number of Investments	466
Total Net Advisory Fees Paid (in thousands)	$1,166
Portfolio Turnover Rate	59%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	54.1%
Pacific Basin	31.1%
North America	10.9%
Middle East/Central Asia	3.2%
South Asia	0.4%
Africa	0.2%
Latin America	0.1%

Country Breakdown (% of Investments)

Japan	19.0%
Germany	11.2%
United States	10.7%
France	9.0%
United Kingdom	8.1%
Netherlands	6.9%
Australia	6.2%
Switzerland	4.7%
Spain	3.5%
Singapore	2.2%
Other	18.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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: 12.8px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.harborcapital.com/documents/fund

Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$63	1.21%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 63

Expense Ratio, Percent

1.21%

AssetsNet

$ 453,510,000

Holdings Count | Holding

466

Advisory Fees Paid, Amount

$ 1,166,000

InvestmentCompanyPortfolioTurnover

59.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$453,510
Number of Investments	466
Total Net Advisory Fees Paid (in thousands)	$1,166
Portfolio Turnover Rate	59%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	54.1%
Pacific Basin	31.1%
North America	10.9%
Middle East/Central Asia	3.2%
South Asia	0.4%
Africa	0.2%
Latin America	0.1%

Country Breakdown (% of Investments)

Japan	19.0%
Germany	11.2%
United States	10.7%
France	9.0%
United Kingdom	8.1%
Netherlands	6.9%
Australia	6.2%
Switzerland	4.7%
Spain	3.5%
Singapore	2.2%
Other	18.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$42	0.82%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.82%

AssetsNet

$ 183,641,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 805,000

InvestmentCompanyPortfolioTurnover

17.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$183,641
Number of Investments	61
Total Net Advisory Fees Paid (in thousands)	$805
Portfolio Turnover Rate	17%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	60.4%
Pacific Basin	38.0%
North America	1.6%

Country Breakdown (% of Investments)

Japan	29.9%
United Kingdom	17.6%
Switzerland	7.5%
Netherlands	4.8%
Belgium	4.6%
France	3.8%
Australia	3.4%
Finland	3.4%
Ireland	3.3%
Luxembourg	3.3%
Sweden	3.3%
Other	15.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$47	0.90%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 47

Expense Ratio, Percent

0.90%

AssetsNet

$ 183,641,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 805,000

InvestmentCompanyPortfolioTurnover

17.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$183,641
Number of Investments	61
Total Net Advisory Fees Paid (in thousands)	$805
Portfolio Turnover Rate	17%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	60.4%
Pacific Basin	38.0%
North America	1.6%

Country Breakdown (% of Investments)

Japan	29.9%
United Kingdom	17.6%
Switzerland	7.5%
Netherlands	4.8%
Belgium	4.6%
France	3.8%
Australia	3.4%
Finland	3.4%
Ireland	3.3%
Luxembourg	3.3%
Sweden	3.3%
Other	15.1%

C000165336

Shareholder Report [Line Items]

Fund Name

Harbor International Small Cap Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRISX

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

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

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.15%

AssetsNet

$ 183,641,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 805,000

InvestmentCompanyPortfolioTurnover

17.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$183,641
Number of Investments	61
Total Net Advisory Fees Paid (in thousands)	$805
Portfolio Turnover Rate	17%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	60.4%
Pacific Basin	38.0%
North America	1.6%

Country Breakdown (% of Investments)

Japan	29.9%
United Kingdom	17.6%
Switzerland	7.5%
Netherlands	4.8%
Belgium	4.6%
France	3.8%
Australia	3.4%
Finland	3.4%
Ireland	3.3%
Luxembourg	3.3%
Sweden	3.3%
Other	15.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$65	1.26%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 65

Expense Ratio, Percent

1.26%

AssetsNet

$ 183,641,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 805,000

InvestmentCompanyPortfolioTurnover

17.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$183,641
Number of Investments	61
Total Net Advisory Fees Paid (in thousands)	$805
Portfolio Turnover Rate	17%

Holdings [Text Block]

Region Breakdown (% of Investments)

Value	Value
Europe	60.4%
Pacific Basin	38.0%
North America	1.6%

Country Breakdown (% of Investments)

Japan	29.9%
United Kingdom	17.6%
Switzerland	7.5%
Netherlands	4.8%
Belgium	4.6%
France	3.8%
Australia	3.4%
Finland	3.4%
Ireland	3.3%
Luxembourg	3.3%
Sweden	3.3%
Other	15.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$30	0.61%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 30

Expense Ratio, Percent

0.61%

AssetsNet

$ 1,310,985,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 4,867,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,310,985
Number of Investments	44
Total Net Advisory Fees Paid (in thousands)	$4,867
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	20.5%
Information Technology	15.0%
Materials	13.1%
Health Care	10.2%
Industrials	10.1%
Consumer Discretionary	7.7%
Utilities	7.5%
Consumer Staples	5.8%
Communication Services	4.7%
Energy	3.8%
Real Estate	1.6%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$33	0.69%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 33

Expense Ratio, Percent

0.69%

AssetsNet

$ 1,310,985,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 4,867,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,310,985
Number of Investments	44
Total Net Advisory Fees Paid (in thousands)	$4,867
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	20.5%
Information Technology	15.0%
Materials	13.1%
Health Care	10.2%
Industrials	10.1%
Consumer Discretionary	7.7%
Utilities	7.5%
Consumer Staples	5.8%
Communication Services	4.7%
Energy	3.8%
Real Estate	1.6%

C000001989

Shareholder Report [Line Items]

Fund Name

Harbor Large Cap Value Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRLVX

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$46	0.94%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 46

Expense Ratio, Percent

0.94%

AssetsNet

$ 1,310,985,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 4,867,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,310,985
Number of Investments	44
Total Net Advisory Fees Paid (in thousands)	$4,867
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	20.5%
Information Technology	15.0%
Materials	13.1%
Health Care	10.2%
Industrials	10.1%
Consumer Discretionary	7.7%
Utilities	7.5%
Consumer Staples	5.8%
Communication Services	4.7%
Energy	3.8%
Real Estate	1.6%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$51	1.05%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 51

Expense Ratio, Percent

1.05%

AssetsNet

$ 1,310,985,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 4,867,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,310,985
Number of Investments	44
Total Net Advisory Fees Paid (in thousands)	$4,867
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	20.5%
Information Technology	15.0%
Materials	13.1%
Health Care	10.2%
Industrials	10.1%
Consumer Discretionary	7.7%
Utilities	7.5%
Consumer Staples	5.8%
Communication Services	4.7%
Energy	3.8%
Real Estate	1.6%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$38	0.80%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 38

Expense Ratio, Percent

0.80%

AssetsNet

$ 157,541,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 618,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$157,541
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$618
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	24.6%
Financials	19.7%
Information Technology	13.4%
Health Care	12.8%
Consumer Discretionary	9.4%
Real Estate	7.4%
Materials	5.9%
Energy	3.3%
Utilities	2.1%
Consumer Staples	1.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$42	0.88%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.88%

AssetsNet

$ 157,541,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 618,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$157,541
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$618
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	24.6%
Financials	19.7%
Information Technology	13.4%
Health Care	12.8%
Consumer Discretionary	9.4%
Real Estate	7.4%
Materials	5.9%
Energy	3.3%
Utilities	2.1%
Consumer Staples	1.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$59	1.24%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.24%

AssetsNet

$ 157,541,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 618,000

InvestmentCompanyPortfolioTurnover

8.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$157,541
Number of Investments	59
Total Net Advisory Fees Paid (in thousands)	$618
Portfolio Turnover Rate	8%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	24.6%
Financials	19.7%
Information Technology	13.4%
Health Care	12.8%
Consumer Discretionary	9.4%
Real Estate	7.4%
Materials	5.9%
Energy	3.3%
Utilities	2.1%
Consumer Staples	1.4%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$37	0.77%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 37

Expense Ratio, Percent

0.77%

AssetsNet

$ 320,992,000

Holdings Count | Holding

175

Advisory Fees Paid, Amount

$ 1,332,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$320,992
Number of Investments	175
Total Net Advisory Fees Paid (in thousands)	$1,332
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	23.0%
Industrials	14.4%
Consumer Discretionary	13.8%
Information Technology	9.8%
Health Care	9.6%
Consumer Staples	9.0%
Real Estate	5.0%
Energy	4.5%
Materials	3.9%
Utilities	3.9%
Communication Services	3.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$41	0.85%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.85%

AssetsNet

$ 320,992,000

Holdings Count | Holding

175

Advisory Fees Paid, Amount

$ 1,332,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$320,992
Number of Investments	175
Total Net Advisory Fees Paid (in thousands)	$1,332
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	23.0%
Industrials	14.4%
Consumer Discretionary	13.8%
Information Technology	9.8%
Health Care	9.6%
Consumer Staples	9.0%
Real Estate	5.0%
Energy	4.5%
Materials	3.9%
Utilities	3.9%
Communication Services	3.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$53	1.10%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 53

Expense Ratio, Percent

1.10%

AssetsNet

$ 320,992,000

Holdings Count | Holding

175

Advisory Fees Paid, Amount

$ 1,332,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$320,992
Number of Investments	175
Total Net Advisory Fees Paid (in thousands)	$1,332
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	23.0%
Industrials	14.4%
Consumer Discretionary	13.8%
Information Technology	9.8%
Health Care	9.6%
Consumer Staples	9.0%
Real Estate	5.0%
Energy	4.5%
Materials	3.9%
Utilities	3.9%
Communication Services	3.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$58	1.21%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 58

Expense Ratio, Percent

1.21%

AssetsNet

$ 320,992,000

Holdings Count | Holding

175

Advisory Fees Paid, Amount

$ 1,332,000

InvestmentCompanyPortfolioTurnover

6.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$320,992
Number of Investments	175
Total Net Advisory Fees Paid (in thousands)	$1,332
Portfolio Turnover Rate	6%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Financials	23.0%
Industrials	14.4%
Consumer Discretionary	13.8%
Information Technology	9.8%
Health Care	9.6%
Consumer Staples	9.0%
Real Estate	5.0%
Energy	4.5%
Materials	3.9%
Utilities	3.9%
Communication Services	3.1%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$37	0.79%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 37

Expense Ratio, Percent

0.79%

AssetsNet

$ 1,799,802,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 7,152,000

InvestmentCompanyPortfolioTurnover

51.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,799,802
Number of Investments	70
Total Net Advisory Fees Paid (in thousands)	$7,152
Portfolio Turnover Rate	51%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Health Care	30.1%
Industrials	24.2%
Information Technology	17.6%
Financials	12.2%
Consumer Discretionary	7.5%
Materials	3.0%
Consumer Staples	2.9%
Energy	2.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$41	0.87%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.87%

AssetsNet

$ 1,799,802,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 7,152,000

InvestmentCompanyPortfolioTurnover

51.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,799,802
Number of Investments	70
Total Net Advisory Fees Paid (in thousands)	$7,152
Portfolio Turnover Rate	51%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Health Care	30.1%
Industrials	24.2%
Information Technology	17.6%
Financials	12.2%
Consumer Discretionary	7.5%
Materials	3.0%
Consumer Staples	2.9%
Energy	2.5%

C000001986

Shareholder Report [Line Items]

Fund Name

Harbor Small Cap Growth Fund

Class Name

Administrative Class

Trading Symbol

Ticker: HRSGX

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$52	1.12%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 52

Expense Ratio, Percent

1.12%

AssetsNet

$ 1,799,802,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 7,152,000

InvestmentCompanyPortfolioTurnover

51.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,799,802
Number of Investments	70
Total Net Advisory Fees Paid (in thousands)	$7,152
Portfolio Turnover Rate	51%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Health Care	30.1%
Industrials	24.2%
Information Technology	17.6%
Financials	12.2%
Consumer Discretionary	7.5%
Materials	3.0%
Consumer Staples	2.9%
Energy	2.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$58	1.23%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 58

Expense Ratio, Percent

1.23%

AssetsNet

$ 1,799,802,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 7,152,000

InvestmentCompanyPortfolioTurnover

51.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,799,802
Number of Investments	70
Total Net Advisory Fees Paid (in thousands)	$7,152
Portfolio Turnover Rate	51%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Health Care	30.1%
Industrials	24.2%
Information Technology	17.6%
Financials	12.2%
Consumer Discretionary	7.5%
Materials	3.0%
Consumer Staples	2.9%
Energy	2.5%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Retirement Class	$37	0.80%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 37

Expense Ratio, Percent

0.80%

AssetsNet

$ 1,996,981,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,787,000

InvestmentCompanyPortfolioTurnover

1.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,996,981
Number of Investments	57
Total Net Advisory Fees Paid (in thousands)	$8,787
Portfolio Turnover Rate	1%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	29.8%
Financials	27.1%
Information Technology	13.1%
Consumer Discretionary	7.8%
Energy	5.7%
Real Estate	4.8%
Health Care	4.0%
Materials	3.9%
Utilities	2.1%
Consumer Staples	1.7%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Institutional Class	$41	0.88%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.88%

AssetsNet

$ 1,996,981,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,787,000

InvestmentCompanyPortfolioTurnover

1.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,996,981
Number of Investments	57
Total Net Advisory Fees Paid (in thousands)	$8,787
Portfolio Turnover Rate	1%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	29.8%
Financials	27.1%
Information Technology	13.1%
Consumer Discretionary	7.8%
Energy	5.7%
Real Estate	4.8%
Health Care	4.0%
Materials	3.9%
Utilities	2.1%
Consumer Staples	1.7%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Administrative Class	$53	1.13%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 53

Expense Ratio, Percent

1.13%

AssetsNet

$ 1,996,981,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,787,000

InvestmentCompanyPortfolioTurnover

1.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,996,981
Number of Investments	57
Total Net Advisory Fees Paid (in thousands)	$8,787
Portfolio Turnover Rate	1%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	29.8%
Financials	27.1%
Information Technology	13.1%
Consumer Discretionary	7.8%
Energy	5.7%
Real Estate	4.8%
Health Care	4.0%
Materials	3.9%
Utilities	2.1%
Consumer Staples	1.7%

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, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

Semi-Annual Shareholder Report

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)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*}
Investor Class	$58	1.24%

Footnote	Description
Footnote^*	Annualized

Expenses Paid, Amount

$ 58

Expense Ratio, Percent

1.24%

AssetsNet

$ 1,996,981,000

Holdings Count | Holding

Advisory Fees Paid, Amount

$ 8,787,000

InvestmentCompanyPortfolioTurnover

1.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets (in thousands)	$1,996,981
Number of Investments	57
Total Net Advisory Fees Paid (in thousands)	$8,787
Portfolio Turnover Rate	1%

Holdings [Text Block]

Sector Allocation (% of Investments)

Value	Value
Industrials	29.8%
Financials	27.1%
Information Technology	13.1%
Consumer Discretionary	7.8%
Energy	5.7%
Real Estate	4.8%
Health Care	4.0%
Materials	3.9%
Utilities	2.1%
Consumer Staples	1.7%