v3.20.1
Income taxes - Other (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Reconciliation of income taxes    
Tax expense $ 1.5 $ 0.6
Valuation allowance 136.7  
Increase (decrease) in the valuation allowance (8.7) (1.6)
Withholding and state taxes   0.4
Operating in countries with different income tax rates 1.4 0.3
Foreign exchange 2.0 0.7
US    
Reconciliation of income taxes    
Increase (decrease) in the valuation allowance $ (2.8) $ (3.3)
Canada.    
Reconciliation of income taxes    
Enacted statutory income tax rate 27.00% 27.00%
Computed income tax (benefit) expense at Canadian statutory rate $ 6.8 $ 0.8
Increase (decrease) in the valuation allowance $ 5.9 $ 1.7