Debt - Narrative (Details)			1 Months Ended	9 Months Ended
	Jul. 30, 2025 USD ($)	Aug. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Debt Instrument [Line Items]
Proceeds from short-term financings				$ 0	$ 100,000,000
Repayment of short-term financings				25,000,000	$ 109,820,000
Short-term financing				0		$ 120,000,000
Revolving line of credit, long-term				95,000,000		0
Debt, long-term and short-term, combined amount				96,700,000
Accrued unpaid interest				300,000		1,200,000
Previous Shareholder Loan Agreements, Weichai | Subordinated Debt
Debt Instrument [Line Items]
Payment for debt extinguishment or debt prepayment cost		$ 60,000,000
Short-term financing		$ 25,000,000
Shareholder’s Loan Agreement | Subordinated Debt
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)		4.05%
Debt instrument, face amount		$ 105,000,000.0
Debt instrument, incremental borrowing cost (as percent)		1.00%
Debt instrument, amount not subject to subordination		$ 10,000,000
Short-term financing				0		25,000,000
Repayments of long-term debt			$ 10,200,000
Revolving Credit Facility | Revolving Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 135,000,000.0
Basis spread on variable rate (as percent)	2.10%
Debt issuance costs	$ 1,200,000
Revolving line of credit, long-term				95,000,000
Revolving Credit Facility | Revolving Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 135,000,000	$ 120,000,000.0
Basis spread on variable rate (as percent)		2.00%
Debt issuance costs		$ 600,000
Proceeds from short-term financings		100,000,000
Short-term financing				$ 0		$ 95,000,000
Majority shareholder ownership threshold for variable rate increase (as percent)	0.50
Revolving Credit Facility | Revolving Credit Agreement - In Event Majority Shareholder Holds Less Than 50% Of Equity | Line of Credit
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	2.60%
Revolving Credit Facility | Fourth Amended And Restated Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Repayment of short-term financings		$ 40,000,000