v3.26.3
Expense Example
Oct. 01, 2026
USD ($)
Thornburg International Growth Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 581
Expense Example, with Redemption, 3 Years 869
Expense Example, with Redemption, 5 Years 1,177
Expense Example, with Redemption, 10 Years 2,050
Thornburg International Growth Fund - Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 336
Expense Example, with Redemption, 3 Years 781
Expense Example, with Redemption, 5 Years 1,352
Expense Example, with Redemption, 10 Years 2,905
Thornburg International Growth Fund - Class I  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 96
Expense Example, with Redemption, 3 Years 334
Expense Example, with Redemption, 5 Years 591
Expense Example, with Redemption, 10 Years 1,326
Thornburg International Growth Fund - Class R6  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 88
Expense Example, with Redemption, 3 Years 313
Expense Example, with Redemption, 5 Years 557
Expense Example, with Redemption, 10 Years 1,255
Thornburg International Growth Fund - Class R3  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 147
Expense Example, with Redemption, 3 Years 648
Expense Example, with Redemption, 5 Years 1,177
Expense Example, with Redemption, 10 Years 2,626
Thornburg International Growth Fund - Class R4  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 121
Expense Example, with Redemption, 3 Years 574
Expense Example, with Redemption, 5 Years 1,054
Expense Example, with Redemption, 10 Years 2,378
Thornburg International Growth Fund - Class R5  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 96
Expense Example, with Redemption, 3 Years 474
Expense Example, with Redemption, 5 Years 877
Expense Example, with Redemption, 10 Years $ 2,005