XML 83 R52.htm IDEA: XBRL DOCUMENT v3.21.1
CONTRACT ACCOUNTING (Schedule of billings in excess of costs and estimated earnings) (Details) - USD ($)
Mar. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Contractors [Abstract]      
Billings and/or cash receipts on uncompleted contracts $ 2,530,216 $ 2,978,007 $ 35,665
Less: Costs and estimated earnings recognized   (2,268,454) (27,004)
Contract liabilities $ 166,033 $ 709,553 $ 8,661