v3.25.4
Harbor Active Small Cap ETF Average Annual Total Returns
 12 Months Ended 15 Months Ended 16 Months Ended 18 Months Ended 28 Months Ended 33 Months Ended 38 Months Ended 39 Months Ended 47 Months Ended 60 Months Ended 120 Months Ended 132 Months Ended 188 Months Ended
Oct. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
 [2]
Dec. 31, 2025
Dec. 31, 2025
 [4]
Dec. 31, 2025
Dec. 31, 2025
 [6]
Dec. 31, 2025
 [7]
Dec. 31, 2025
 [8]
Dec. 31, 2025
 [9]
Dec. 31, 2025
 [10]
Dec. 31, 2025
 [10]
Dec. 31, 2025
 [11]
Dec. 31, 2025
 [10]
S&P 500 Index (reflects no deduction for fees, expenses or taxes)[Member]                                
Prospectus [Line Items]                                
Average Annual Return, Percent   17.88% [1] 16.02% 17.74% [1] 19.14% 16.32% [3] 22.03% 22.50% [5] 20.88% 24.11% 12.50% 12.43% 14.42% 14.82% 13.53% 13.94%
Russell 2000® Index (reflects no deduction for fees, expenses or taxes)[Member]                                
Prospectus [Line Items]                                
Average Annual Return, Percent   12.81% [12]   11.32% [12]   16.10% [13]   14.76% [14]                
NONE or SAME                                
Prospectus [Line Items]                                
Average Annual Return, Percent   (6.23%)   3.44%                        
Performance Inception Date Aug. 28, 2024                              
NONE or SAME | After Taxes on Distributions                                
Prospectus [Line Items]                                
Average Annual Return, Percent   (6.85%)   2.80%                        
NONE or SAME | After Taxes on Distributions and Sales                                
Prospectus [Line Items]                                
Average Annual Return, Percent   (3.43%)   2.51%                        
[1] This index represents a broad measure of market performance.
[2] This index represents a broad measure of market performance.
[3] This index represents a broad measure of market performance.
[4] This index represents a broad measure of market performance.
[5] This index represents a broad measure of market performance.
[6] This index represents a broad measure of market performance.
[7] This index represents a broad measure of market performance.
[8] This index represents a broad measure of market performance.
[9] This index represents a broad measure of market performance.
[10] This index represents a broad measure of market performance.
[11] This index represents a broad measure of market performance.
[12] The Advisor considers this index to be representative of the Fund’s principal investment strategies and therefore the appropriate benchmark index for the Fund for performance comparison purposes.
[13] The Advisor considers this index to be representative of the Fund’s principal investment strategies and therefore the appropriate benchmark index for the Fund for performance comparison purposes.
[14] The Advisor considers this index to be representative of the Fund’s principal investment strategies and therefore the appropriate benchmark index for the Fund for performance comparison purposes.