Commitments and Contingencies - Related Party Transactions (Details)			3 Months Ended
	Dec. 07, 2023 USD ($)	Dec. 07, 2022 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)
Selling, General and Administrative Expense
Selling, general and administrative			$ 6,921,000	$ 6,783,000
Affiliated Entity
Selling, General and Administrative Expense
Percentage of PrivateCo's income (as a percent)	90
Other income			500,000
Affiliated Entity \| Capstone Green Energy Corporation (Reorganized PrivateCo)
Selling, General and Administrative Expense
Related party transaction, annual royalty payment	$ 100,000
Affiliated Entity \| Capstone Green Energy LLC (Operating Subsidiary)
Selling, General and Administrative Expense
Services fee		$ 2,500,000
Services fee cap threshold incremental percentage (as a percent)		3.50%
Services fee cap incremental percentage (as a percent)		1.75%
Immediate Family Member of Management or Principal Owner
Selling, General and Administrative Expense
Selling, general and administrative			600,000	$ 1,200,000
Related party transaction, estimated potential bonus			$ 0