Note 4 - Costs, Estimated Earnings, and Billings on Uncompleted Contracts (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Costs incurred on contract in progress	$ 7,801,867	$ 7,695,281
Estimated earnings	7,262,926	7,635,114
Total	15,064,793	15,330,395
Billings to date	(10,768,756)	(10,695,377)
Cost in excess of billing, net	4,296,037	4,635,018
Included in accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on contracts in progress	4,325,998	$ 4,635,018
Billings in excess of costs and estimated earnings on contracts in progress	(29,961)
Cost in excess of billing, net	$ 4,296,037	$ 4,635,018