Note 14 - Subsequent Events - Sale of 555 Building - Proforma Balance Sheet (Details) - USD ($)		Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and cash equivalents		$ 5,387,896		$ 7,699,335
Accounts receivable, net		1,147,451		1,047,728
Contract assets		1,066,382		494,281
Inventories, net		1,297,202		1,123,839
Taxes Receivable		715,599		715,599
Other current assets		460,260		709,175
Assets held for sale		16,181,368		0
Total Current Assets		26,256,158		11,789,957
Property, plant and equipment, net		12,405,495		28,843,563
Intangible assets, net		234,633		288,657
Other assets		23,318		13,748
Total Assets		38,919,604		40,935,925	$ 48,325,000
Accounts payable		910,731		817,933
Accrued expenses		1,766,245		1,409,039
Current maturities of long-term debt		1,915,508		690,667
Contract Liabilities		1,001,071		786,657
Liabilities held for sale		9,123,151		0
Total Current Liabilities		14,716,706		3,704,296
Long-term debt, net of current portion		0		13,106,057
Total Liabilities		14,716,706		16,810,353
Commitments and contingencies (see note 13)
Stockholders’ Equity:
Common stock - $0.01 par value – 20,000,000 shares authorized; issued and outstanding 6,684,281 at June 30, 2021 and 6,678,698 at December 31, 2020		66,842		66,786
Additional paid-in capital		27,074,079		26,961,684
Retained earnings		(2,938,023)		(2,902,898)
Total Stockholders’ Equity		24,202,898	$ 22,670,395	24,125,572	$ 30,623,246	$ 31,688,971	$ 29,957,845
Total Liabilities and Stockholders’ Equity		38,919,604		$ 40,935,925
Scenario, Adjustment [Member]
Cash and cash equivalents	[1]	13,976,766
Other current assets	[2]	(110,534)
Assets held for sale	[3]	(16,181,368)
Total Current Assets		(2,315,136)
Total Assets		(2,315,136)
Accrued expenses	[4]	(142,255)
Liabilities held for sale	[5]	(9,123,151)
Total Current Liabilities		(9,265,406)
Total Liabilities		(9,265,406)
Stockholders’ Equity:
Retained earnings	[6]	6,950,270
Total Stockholders’ Equity		6,950,270
Total Liabilities and Stockholders’ Equity		(2,315,136)
Pro Forma [Member]
Cash and cash equivalents		19,364,662
Accounts receivable, net		1,147,451
Contract assets		1,066,382
Inventories, net		1,297,202
Taxes Receivable		715,599
Other current assets		349,726
Total Current Assets		23,941,022
Property, plant and equipment, net		12,405,495
Intangible assets, net		234,633
Other assets		23,318
Total Assets		36,604,468
Accounts payable		910,731
Accrued expenses		1,623,990
Current maturities of long-term debt		1,915,508
Contract Liabilities		1,001,071
Total Current Liabilities		5,451,300
Long-term debt, net of current portion		0
Total Liabilities		5,451,300
Commitments and contingencies (see note 13)
Stockholders’ Equity:
Common stock - $0.01 par value – 20,000,000 shares authorized; issued and outstanding 6,684,281 at June 30, 2021 and 6,678,698 at December 31, 2020		66,842
Additional paid-in capital		27,074,079
Retained earnings		4,012,247
Total Stockholders’ Equity		31,153,168
Total Liabilities and Stockholders’ Equity		$ 36,604,468

[1] Net proceeds from sale of building, net of full payment of 555 Building mortgage, and related closing fees.

[2] Receipt of apportionment of prepaid Pilot taxes, and broker fees on rental space at 555 Building.

[3] Building related assets sold.

[4] Payment of 555 Building tenant escrow deposit to buyer of 555 Building.

[5] Mortgage at 555 Building paid off at closing of sale of building.

[6] Approximate net income from sale of building net of related costs