Acquisitions - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Jan. 31, 2025	Jan. 01, 2024	Jun. 30, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Business Combination [Line Items]
Amortized, description				The supplier relationships and trade name shall be amortized on a straight-line basis over a useful life of six and three years, respectively.
Goodwill				$ 102,875	$ 97,792	$ 89,388	$ 88,910
Sierra Acquisition
Business Combination [Line Items]
Purchase consideration		$ 13,700
Sierra Acquisition | Supplier Relationships
Business Combination [Line Items]
Intangible assets		5,100
Sierra Acquisition | Trade Name
Business Combination [Line Items]
Intangible assets		300
Sierra Acquisition | Goodwill
Business Combination [Line Items]
Intangible assets		$ 7,900
Auction Software Acquisition
Business Combination [Line Items]
Purchase price, net	$ 6,500
Issuance of stock	900
Purchase consideration	$ 7,400
Increase in goodwill balance			$ 300
Goodwill			5,100
Intangible assets			$ 2,600	$ 2,700