XML 54 R43.htm IDEA: XBRL DOCUMENT v3.20.2
Research Funding (Details) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended
May 31, 2019
Mar. 31, 2018
Dec. 31, 2017
May 31, 2017
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Feb. 28, 2017
Deferred Revenue Arrangement [Line Items]                    
Grants awarded   $ 8,100,000               $ 12,200,000
Funding of grant award       $ 5,700,000            
Milestone payment received on grant award     $ 1,900,000              
Progress payment received on grant award   $ 300,000                
Research and Development Arrangement with Federal Government, Customer Funding to Offset Costs Incurred $ 200,000                  
Accrued grant funding         $ 229,000   $ 229,000   $ 1,600,000  
Amortization of accrued grant funding to offset expense         700,000 $ 700,000 1,400,000 $ 1,300,000    
Accrued Liabilities [Member]                    
Deferred Revenue Arrangement [Line Items]                    
Accrued grant funding         $ 200,000   $ 200,000