v3.26.3
S000000777 [Member] Expense Example - Putnam Small Cap Growth Fund
Jun. 30, 2026
USD ($)
Class C shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 289
Expense Example, with Redemption, 3 Years 585
Expense Example, with Redemption, 5 Years 1,006
Expense Example, with Redemption, 10 Years 1,985
Class Y shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 88
Expense Example, with Redemption, 3 Years 274
Expense Example, with Redemption, 5 Years 476
Expense Example, with Redemption, 10 Years 1,060
Class A shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 682
Expense Example, with Redemption, 3 Years 908
Expense Example, with Redemption, 5 Years 1,152
Expense Example, with Redemption, 10 Years 1,849
Class R shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 138
Expense Example, with Redemption, 3 Years 431
Expense Example, with Redemption, 5 Years 745
Expense Example, with Redemption, 10 Years 1,636
Class R6 Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 76
Expense Example, with Redemption, 3 Years 237
Expense Example, with Redemption, 5 Years 412
Expense Example, with Redemption, 10 Years $ 919