Goodwill and Intangible Assets - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 2,061	$ 3,255	$ 4,993
Gross Carrying Amount	70,760	85,527
Accumulated Amortization	(68,743)	(81,428)
Total	$ 2,017	$ 4,099
Weighted Average Life in Years	5 years	6 years
Completed technology
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 500	$ 1,027	1,766
Gross Carrying Amount	67,760	71,808
Accumulated Amortization	(66,843)	(70,391)
Total	$ 917	$ 1,417
Weighted Average Life in Years	5 years	5 years
Customer contracts and relationships
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,561	$ 2,082	2,927
Gross Carrying Amount	3,000	13,719
Accumulated Amortization	(1,900)	(11,037)
Total	$ 1,100	$ 2,682
Weighted Average Life in Years	5 years	9 years
Trade names
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 0	$ 0	125
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 0	$ 146	$ 175
Weighted Average Life in Years	2 years