Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017		Jan. 01, 2017	[1]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	$ 198.4	$ 23.2	[1]	$ 23.2
Intangible assets	283.6	21.6	[1]	$ 25.5
Intellectual property
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	0.0	0.0
Other intangible assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	269.8	10.4
Computer software assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	13.8	11.2
Cost
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	253.8	78.6
Intangible assets	909.4	633.6
Cost | Intellectual property
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	111.3	111.3
Cost | Other intangible assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	508.0	237.0
Cost | Computer software assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	290.1	285.3
Accumulated Amortization and Impairment
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	(55.4)	(55.4)
Intangible assets	(625.8)	(612.0)
Accumulated Amortization and Impairment | Intellectual property
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	(111.3)	(111.3)
Accumulated Amortization and Impairment | Other intangible assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	(238.2)	(226.6)
Accumulated Amortization and Impairment | Computer software assets
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Intangible assets	$ (276.3)	$ (274.1)

[1] Certain prior period figures have been restated to reflect the adoption of IFRS 15 (see note 2)