Goodwill and Intangible Assets (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2017 USD ($) store	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)
Goodwill [Line Items]
Goodwill related to acquisition		$ 536,111,000		$ 536,111,000		$ 537,791,000
Impairment losses in connection with the goodwill				0
Impairment losses in connection with the intangible assets				0
Amortization expense related to other intangible assets		3,200,000	$ 3,200,000	$ 8,800,000	$ 9,900,000
Chalut | Canada
Goodwill [Line Items]
Number of professional-only beauty supply stores | store	21
Cost of acquisition	$ 8,800,000
Goodwill related to acquisition	$ 5,500,000
Amount recognized a decrease in goodwill with a corresponding increase in intangible assets		$ 4,700,000