Annual report pursuant to Section 13 and 15(d)

Income taxes (Narrative) (Details)

v3.22.0.1
Income taxes (Narrative) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2021
USD ($)
Operating Loss Carryforwards [Line Items]  
Increase (decrease) in deferred tax asset valuation allowance $ 4.0
Federal [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards 264.9
Portion of federal and state net operating loss carryforwards subject to an 80% limitation on taxable income, that do not expire and will carry forward indefinitely 139.7
Federal [Member] | 2026 [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards $ 125.2
Federal [Member] | Minimum [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards, expiration date Dec. 31, 2026
Federal [Member] | Maximum [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards, expiration date Dec. 31, 2037
State [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards $ 219.6
Portion of federal and state net operating loss carryforwards subject to an 80% limitation on taxable income, that do not expire and will carry forward indefinitely 72.5
State [Member] | 2037 [Member]  
Operating Loss Carryforwards [Line Items]  
Net operating loss carry forwards $ 147.1