Segments and Disaggregated Revenue - Schedule of Disaggregation of Net Sales by Segment (Details) - Sales Revenue, Net	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Sally Beauty Supply
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Sally Beauty Supply | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Sally Beauty Supply | Hair color | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	29.40%	26.90%	26.00%
Sally Beauty Supply | Hair care | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	20.40%	20.90%	21.10%
Sally Beauty Supply | Skin and nail care | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	14.80%	15.70%	15.70%
Sally Beauty Supply | Styling tools | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	13.50%	13.90%	14.10%
Sally Beauty Supply | Multicultural products | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.10%	7.50%	7.90%
Sally Beauty Supply | Salon supplies and accessories | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	6.60%	7.10%	7.30%
Sally Beauty Supply | Other Beauty items | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	8.20%	8.00%	7.90%
Sally Beauty Supply | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	96.90%	97.50%	98.10%
Sally Beauty Supply | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	2.80%	2.20%	1.60%
Sally Beauty Supply | Sales channel, through intermediary | Franchise stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	0.30%	0.30%	0.30%
Beauty Systems Group
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Beauty Systems Group | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Beauty Systems Group | Hair color | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	39.50%	38.40%	37.00%
Beauty Systems Group | Hair care | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	35.10%	33.70%	34.40%
Beauty Systems Group | Skin and nail care | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	8.10%	8.70%	9.00%
Beauty Systems Group | Styling tools | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	3.40%	3.90%	4.20%
Beauty Systems Group | Other Beauty items | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	6.30%	6.70%	6.90%
Beauty Systems Group | Promotional items | Product Concentration Risk
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.60%	8.60%	8.50%
Beauty Systems Group | Sales channel, directly to consumer | Company-operated stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	69.40%	68.70%	68.40%
Beauty Systems Group | Sales channel, through intermediary | E-commerce
Disaggregation Of Revenue [Line Items]
Percentage of net sales	4.80%	3.70%	3.30%
Beauty Systems Group | Sales channel, through intermediary | Franchise stores
Disaggregation Of Revenue [Line Items]
Percentage of net sales	7.60%	7.70%	7.70%
Beauty Systems Group | Sales channel, through intermediary | Distributor sales consultants
Disaggregation Of Revenue [Line Items]
Percentage of net sales	18.20%	19.90%	20.60%