Earnings (Loss) Per Share - Computation of Weighted Average Shares Outstanding (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income (loss) from continuing operations	$ 76.8	$ 79.6	$ (77.0)
Net income attributable to the non-controlling interests	0.0	(0.7)	(1.5)
Net income (loss) from continuing operations attributable to common stockholders	$ 76.8	$ 78.9	$ (78.5)
Basic weighted average common stock outstanding (in shares)	248.8	257.6	288.2
Denominator adjustments for diluted EPS:
Number of shares issuable upon conversion of Series A Preferred Stock (in shares)	0.3	2.0	0.0
Number of stock options and RSUs (in shares)	0.8	0.5	0.0
Denominator adjustments for diluted EPS (in shares)	1.1	2.5	0.0
Dilutive weighted average common shares outstanding (in shares)	249.9	260.1	288.2
Earnings (loss) per share from continuing operations attributable to common stockholders:
Basic (in dollars per share)	$ 0.31	$ 0.31	$ (0.27)
Diluted (in dollars per share)	$ 0.31	$ 0.30	$ (0.27)