Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income (loss) attributable to shareholders	$ 3.1	$ 11.7	$ 6.3	$ (20.9)	$ (18.0)	$ (41.4)	$ (33.5)	$ (92.9)	$ 0.2	$ (185.8)	$ (221.3)
Weighted average shares outstanding for basic earnings (loss) per share									217.7	171.2	143.9
Net (loss) earnings per share, basic (USD per share)	$ 0.01	$ 0.05	$ 0.03	$ (0.10)	$ (0.09)	$ (0.22)	$ (0.23)	$ (0.64)	$ 0.00	$ (1.09)	$ (1.54)
Weighted average shares outstanding for diluted earnings (loss) per share (in shares)									224.5	171.2	143.9
Net (loss) earnings per share, diluted (USD per share)	$ 0.01	$ 0.05	$ 0.03	$ (0.10)	$ (0.09)	$ (0.22)	$ (0.23)	$ (0.64)	$ 0.00	$ (1.09)	$ (1.54)
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive effect of stocks									5.3	0.0	0.0
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive effect of stocks									1.5	0.0	0.0