Income taxes (Narrative) (Details) $ in Millions |
12 Months Ended |
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Dec. 31, 2020
USD ($)
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| 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 |
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- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Expiration date of each operating loss carryforward included in operating loss carryforward, in CCYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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