Uncompleted Contracts (Tables)

12 Months Ended

Dec. 31, 2020

Costs, estimated earnings and billings on uncompleted contracts are as follows:

	December 31,			December 31,
	2020			2019

Revenue recognized	$	102,700		$	1,074,800
Less: billings to date		(95,900	)		(832,300	)
Costs and estimated earnings in excess of billings on uncompleted contracts		6,800			242,500

Billings to date		1,716,800			2,707,200
Revenue recognized		(1,392,900	)		(2,380,100	)

Revenue contract liabilities	$	323,900		$	327,100