Segment Reporting - Schedule of Disaggregation of Net Sales by Segment (Details) - Sales Revenue, Net - Product Concentration Risk	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
SBS
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%
SBS | Hair color
Disaggregation Of Revenue [Line Items]
Percentage of net sales	40.50%	39.10%
SBS | Hair care
Disaggregation Of Revenue [Line Items]
Percentage of net sales	23.80%	24.60%
SBS | Styling tools and supplies
Disaggregation Of Revenue [Line Items]
Percentage of net sales	17.30%	18.20%
SBS | Nail
Disaggregation Of Revenue [Line Items]
Percentage of net sales	10.10%	10.10%
SBS | Skin and cosmetics
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.70%	7.40%
SBS | Other Beauty items
Disaggregation Of Revenue [Line Items]
Percentage of net sales	0.60%	0.60%
SBS | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	92.10%	93.30%
SBS | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.90%	6.70%
BSG
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%
BSG | Hair color
Disaggregation Of Revenue [Line Items]
Percentage of net sales	40.10%	39.40%
BSG | Hair care
Disaggregation Of Revenue [Line Items]
Percentage of net sales	42.80%	42.90%
BSG | Styling tools and supplies
Disaggregation Of Revenue [Line Items]
Percentage of net sales	10.70%	10.70%
BSG | Nail
Disaggregation Of Revenue [Line Items]
Percentage of net sales	2.40%	2.40%
BSG | Skin and cosmetics
Disaggregation Of Revenue [Line Items]
Percentage of net sales	3.80%	4.30%
BSG | Other Beauty items
Disaggregation Of Revenue [Line Items]
Percentage of net sales	0.20%	0.30%
BSG | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	69.40%	68.60%
BSG | Sales channel, through intermediary | Distributor sales consultants
Disaggregation Of Revenue [Line Items]
Percentage of net sales	9.60%	10.60%
BSG | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	14.00%	13.80%
BSG | Sales channel, through intermediary | Franchise stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.00%	7.00%