Income Taxes - Income taxes paid (net of refunds received) (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2026	Dec. 31, 2024
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)	$ 191,000	$ 466,000	$ 694,000
Federal
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)		8,000
Virginia
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)	105,000	(63,000)
Texas
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)		24,000
Other states
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)	6,000	(8,000)
Foreign - Netherlands
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)	137,000	444,000
Foreign - South Africa
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income taxes paid (net of refunds received)	$ (57,000)	$ 61,000