Contracts in progress (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Contracts in progress
Revenues recognized to date on contracts in process	$ 127,237,229	$ 114,590,991
Amounts billed to date on contracts in process	(138,121,977)	(121,833,354)
Retainage	2,646,929	2,585,952
Net contract asset (liability)	(8,237,819)	(4,656,411)
Balance Sheet location
Contract assets	3,290,815	4,470,243
Contract liabilities	(11,528,634)	$ (9,126,654)
Revenue remaining performance obligation expected timing of satisfaction
Revenue remaining performance obligation, amount	148,800,000
Amount recognized revenue included in the contract liability balance	5,500,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue remaining performance obligation expected timing of satisfaction
Revenue remaining performance obligation, amount	$ 56,700,000
Revenue remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue remaining performance obligation expected timing of satisfaction
Revenue remaining performance obligation, amount	$ 92,100,000
Revenue remaining performance obligation, expected timing of satisfaction, period	1 year