v3.19.3.a.u2
Income tax expense - NOL (Details)
$ in Millions
Dec. 31, 2019
USD ($)
Operating loss carryforwards  
Net operating loss carryforwards $ 522.9
2029  
Operating loss carryforwards  
Net operating loss carryforwards 27.3
2030  
Operating loss carryforwards  
Net operating loss carryforwards 41.1
2031  
Operating loss carryforwards  
Net operating loss carryforwards 25.8
2032  
Operating loss carryforwards  
Net operating loss carryforwards 19.2
2033  
Operating loss carryforwards  
Net operating loss carryforwards 44.1
2034  
Operating loss carryforwards  
Net operating loss carryforwards 131.4
2035  
Operating loss carryforwards  
Net operating loss carryforwards 154.1
2036  
Operating loss carryforwards  
Net operating loss carryforwards 37.3
2037  
Operating loss carryforwards  
Net operating loss carryforwards 25.6
2038  
Operating loss carryforwards  
Net operating loss carryforwards 10.1
2039  
Operating loss carryforwards  
Net operating loss carryforwards 6.9
US  
Operating loss carryforwards  
Net operating loss carryforwards 411.0
US | 2030  
Operating loss carryforwards  
Net operating loss carryforwards 41.1
US | 2031  
Operating loss carryforwards  
Net operating loss carryforwards 25.8
US | 2032  
Operating loss carryforwards  
Net operating loss carryforwards 13.4
US | 2033  
Operating loss carryforwards  
Net operating loss carryforwards 20.6
US | 2034  
Operating loss carryforwards  
Net operating loss carryforwards 122.3
US | 2035  
Operating loss carryforwards  
Net operating loss carryforwards 154.1
US | 2036  
Operating loss carryforwards  
Net operating loss carryforwards 17.0
US | 2037  
Operating loss carryforwards  
Net operating loss carryforwards 16.7
Canada.  
Operating loss carryforwards  
Net operating loss carryforwards 111.9
Canada. | 2029  
Operating loss carryforwards  
Net operating loss carryforwards 27.3
Canada. | 2032  
Operating loss carryforwards  
Net operating loss carryforwards 5.8
Canada. | 2033  
Operating loss carryforwards  
Net operating loss carryforwards 23.5
Canada. | 2034  
Operating loss carryforwards  
Net operating loss carryforwards 9.1
Canada. | 2036  
Operating loss carryforwards  
Net operating loss carryforwards 20.3
Canada. | 2037  
Operating loss carryforwards  
Net operating loss carryforwards 8.9
Canada. | 2038  
Operating loss carryforwards  
Net operating loss carryforwards 10.1
Canada. | 2039  
Operating loss carryforwards  
Net operating loss carryforwards $ 6.9