Investments - Summary of Investments (Details) - USD ($) $ in Thousands, shares in Millions		3 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value	$ 11,233	$ 11,233	$ 2,675
CSI Compressco [Member]
Schedule of Equity Method Investments [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	3.80%
CSI Compressco [Member]
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value	$ 6,233	$ 6,233	0
Standard Lithium [Member]
Schedule of Equity Method Investments [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		1.6
Sale Of Stock, Consideration Received On Transaction, Gross		$ 17,600
Investments in and Advances to Affiliates, at Fair Value	0	0	2,675
CarbonFree
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value	5,000	5,000	$ 0
CarbonFree | Convertible Debt Securities
Schedule of Equity Method Investments [Line Items]
Debt Securities, Available-for-sale	$ 5,000	$ 5,000