Income Taxes - Effective tax rate and its statutory tax rate (Details) - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2025	Dec. 31, 2024	Dec. 31, 2023
Effective Income Tax Rate Reconciliation, Amount
Federal statutory rate	$ 341,000
State and local taxes, net of federal income tax effect	64,000
Statutory difference between US and foreign jurisdictions	63,000
Change in valuation allowance	3,000
Nontaxable or nondeductible items	5,000
Deferred tax rate change	(887,000)
Other	(18,000)
Total income tax (benefit) expense	$ (313,000)	$ (2,329,000)	$ 20,000
Effective Income Tax Rate Reconciliation, Percent
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%
State and local taxes, net of federal income tax effect	3.90%	1.00%	3.10%
Statutory difference between US and foreign jurisdictions	3.80%	(0.60%)
Changes in Valuation allowance	0.20%	5.40%	(24.60%)
Nontaxable or nondeductible items	0.30%
Deferred tax rate change	(54.60%)
Other	(1.10%)
Effective income tax rate	(19.30%)	25.20%	(0.70%)
Foreign - Netherlands
Effective Income Tax Rate Reconciliation, Amount
Other foreign tax effects	$ 9,000
Effective Income Tax Rate Reconciliation, Percent
Other foreign tax effects	0.60%
Foreign - South Africa
Effective Income Tax Rate Reconciliation, Amount
Other foreign tax effects	$ 107,000
Effective Income Tax Rate Reconciliation, Percent
Other foreign tax effects	6.60%

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other foreign income tax expense (benefit).

No definition available.