Segment Reporting - Schedule of Disaggregation of Net Sales by Segment (Details) - Sales Revenue, Net - Product Concentration Risk	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
SBS
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%	100.00%
SBS | Hair color
Disaggregation Of Revenue [Line Items]
Percentage of net sales	40.60%	40.50%	39.70%	39.60%
SBS | Hair care
Disaggregation Of Revenue [Line Items]
Percentage of net sales	24.20%	23.80%	24.50%	23.80%
SBS | Styling tools and supplies
Disaggregation Of Revenue [Line Items]
Percentage of net sales	16.20%	17.20%	17.10%	18.20%
SBS | Nail
Disaggregation Of Revenue [Line Items]
Percentage of net sales	10.50%	10.10%	10.20%	10.10%
SBS | Skin and cosmetics
Disaggregation Of Revenue [Line Items]
Percentage of net sales	8.10%	7.90%	8.00%	7.60%
SBS | Other Beauty items
Disaggregation Of Revenue [Line Items]
Percentage of net sales	0.40%	0.50%	0.50%	0.70%
SBS | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	93.00%	94.10%	93.20%	93.80%
SBS | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.00%	5.90%	6.80%	6.20%
BSG
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%	100.00%
BSG | Hair color
Disaggregation Of Revenue [Line Items]
Percentage of net sales	41.80%	41.60%	40.90%	40.10%
BSG | Hair care
Disaggregation Of Revenue [Line Items]
Percentage of net sales	41.70%	40.80%	42.10%	42.20%
BSG | Styling tools and supplies
Disaggregation Of Revenue [Line Items]
Percentage of net sales	10.30%	10.60%	10.50%	10.70%
BSG | Nail
Disaggregation Of Revenue [Line Items]
Percentage of net sales	2.50%	2.70%	2.40%	2.70%
BSG | Skin and cosmetics
Disaggregation Of Revenue [Line Items]
Percentage of net sales	3.40%	4.00%	3.70%	4.10%
BSG | Other Beauty items
Disaggregation Of Revenue [Line Items]
Percentage of net sales	0.30%	0.30%	0.40%	0.20%
BSG | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	68.50%	67.60%	68.30%	67.20%
BSG | Sales channel, through intermediary | Distributor sales consultants
Disaggregation Of Revenue [Line Items]
Percentage of net sales	10.70%	11.60%	10.60%	11.90%
BSG | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	13.40%	13.00%	13.70%	13.40%
BSG | Sales channel, through intermediary | Franchise stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.40%	7.80%	7.40%	7.50%