v3.24.3
Debt - Term loan (Details) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2022
Debt Instruments      
Debt instruments issuance cost $ 9,202 $ 5,214  
Remaining aggregate outstanding principal amount paid 1,625,595 1,370,799 $ 770,286
Loss on extinguishment of debt from write-off of unamortized deferred financing costs $ (3,734) (2,395) $ (16,439)
Sally Holdings, LLC | TLB 2030      
Debt Instruments      
Debt instrument, face amount   $ 400,000  
Interest rate 0.50% 0.25%  
Debt instrument maturity terms The TLB 2030 matures on February 28, 2030    
Debt instrument payment terms repayable in quarterly installments equal to 0.25% of the original principal amount of the TLB 2030, with a final installment equal to the entire remaining outstanding principal amount due on the Maturity Date.    
Percentage of principal repayable in quarterly installments equal to a percentage of original principal amount to outstanding principal amount due on maturity date   0.25%  
Interest rate discount   0.75%  
Debt instruments issuance cost   $ 4,700  
Loss on extinguishment of debt from write-off of unamortized deferred financing costs $ (1,700) (1,800)  
Non-cash income from financing activities $ 20,500 $ 7,900  
Sally Holdings, LLC | TLB 2030 | SOFR      
Debt Instruments      
Interest rate   1.75%  
Sally Holdings, LLC | TLB 2030 | Base rate      
Debt Instruments      
Interest rate   0.75%