Annual report pursuant to Section 13 and 15(d)

Income taxes (Narrative) (Details)

v3.21.1
Income taxes (Narrative) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards $ 210.6
Increase (decrease) in deferred tax asset valuation allowance 9.7
Federal [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards $ 110.3
Maximum [Member] | Federal [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards, expiration date Dec. 31, 2037