Note 7 - Loans Payable (Details Textual) | Jan. 28, 2021USD ($) | Jul. 16, 2020USD ($)a | Mar. 29, 2019USD ($) | Jan. 24, 2019USD ($) | Mar. 21, 2018USD ($) | Jan. 31, 2021USD ($) | Jul. 16, 2020USD ($)a | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Mar. 31, 2021USD ($)ft²a |
Cortlandt Manor Medical Center [Member] | | | | | | | | | | |
Area of Real Estate Property (Square Foot) | ft² | | | | | | | | | | 34,000 |
Real Estate Securing Mortgage Loan [Member] | Flowerfield Industrial Park [Member] | | | | | | | | | | |
Area of Real Estate Property (Square Foot) | a | | 31.8 | | | | | 31.8 | | | 31.8 |
Real Estate Securing Mortgage Loan [Member] | Cortlandt Manor Medical Center [Member] | | | | | | | | | | |
Area of Real Estate Property (Square Foot) | a | | 13.8 | | | | | 13.8 | | | |
Non-revolving Credit Line [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | | | $ 3,000,000 | $ 3,000,000 | | | | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | | 240 days | | | | | |
Debt Instrument, Interest and Principal Phase, Term (Month) | | | | 7 years | | | | | | |
Proceeds from Lines of Credit, Total | | | $ 1,100,000 | $ 1,100,000 | | | | | | |
Debt Instrument, Face Amount | | | | 2,200,000 | | | | | | |
Debt Instrument, Unused Borrowing Capacity, Amount | | | | $ 800,000 | | | | | | |
Non-revolving Credit Line [Member] | Interest Only Period of Payments [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 4.75% | | | | | | |
Non-revolving Credit Line [Member] | Prime Rate [Member] | Interest Only Period of Payments [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 1.50% | | | | | | |
Non-revolving Credit Line [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 2.00% | | | | | | |
Debt Instrument, Amortization Period (Year) | | | | 20 years | | | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | | | 3.85% | | | | | | |
Non-revolving Credit Line [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 3.85% | | | | | | |
Non-revolving Credit Line 2 [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | | | $ 3,000,000 | | | | | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | 2 years | | | | | | |
Debt Instrument, Interest and Principal Phase, Term (Month) | | | | 7 years | | | | | | |
Proceeds from Lines of Credit, Total | | | | | | $ 419,932 | | $ 1,000,000 | $ 1,580,068 | |
Non-revolving Credit Line 2 [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Amortization Period (Year) | | | | 20 years | | | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | | | 3.85% | | | | | | |
Non-revolving Credit Line 2 [Member] | Prime Rate [Member] | Interest Only Period of Payments [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 1.00% | | | | | | |
Non-revolving Credit Line 2 [Member] | Prime Rate [Member] | Interest Only Period of Payments [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 4.75% | | | | | | |
Non-revolving Credit Line 2 [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 2.00% | | | | | | |
Non-revolving Credit Line 2 [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | 3.85% | | | | | | |
Non-revolving Credit Line 3 [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | $ 2,500,000 | | | | | $ 2,500,000 | | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | | | | 2 years | | | |
Proceeds from Lines of Credit, Total | $ 670,235 | $ 379,765 | | | | | | | | |
Line of Credit Facility, Remaining Borrowing Capacity | | | | | | | | | | $ 1,450,000 |
Non-revolving Credit Line 3 [Member] | Interest Only Period of Payments [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | 4.75% | | | | | 4.75% | | | |
Non-revolving Credit Line 3 [Member] | Prime Rate [Member] | Interest Only Period of Payments [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | | 1.00% | | | |