Commitments and Contingencies - Narrative (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2016 segment
Environmental Exit Cost [Line Items]
Number of other parties in agreement | segment				7
Estimated reserve, remaining	$ 2,711
Loss contingency receivable	1,076	$ 468
Abrasive particle supply agreement
Environmental Exit Cost [Line Items]
Purchase obligation	11,030
Non-Water Based Carrier Fluid
Environmental Exit Cost [Line Items]
Purchase obligation	15,133
KMG Bernuth
Environmental Exit Cost [Line Items]
Estimated remediation cost	2,508
Loss contingency	$ 26	$ 1,551	$ 9,494