Earnings per Share (EPS) - Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
EPS numerator:
Loss from continuing operations, net of income taxes	$ (59.6)	$ (64.8)	$ (160.3)	$ (1,739.4)
Less: Net income (loss) attributable to noncontrolling interests	8.9	0.1	12.6	(5.1)
Loss from continuing operations attributable to common stockholders	(68.5)	(64.9)	(172.9)	(1,734.3)
Income (loss) from discontinued operations, net of income taxes	24.3	(2.3)	20.0	(6.8)
Net loss attributable to common stockholders	$ (44.2)	$ (67.2)	$ (152.9)	$ (1,741.1)
EPS denominator:
Weighted average shares outstanding — basic and diluted	114.9	97.9	104.9	97.6
Basic EPS attributable to common stockholders:
Basic loss per share	$ (0.38)	$ (0.69)	$ (1.46)	$ (17.83)
Basic and diluted EPS attributable to common stockholders:
Loss from continuing operations	(0.60)	(0.66)	(1.65)	(17.76)
Income (loss) from discontinued operations	0.22	(0.03)	0.19	(0.07)
Net loss attributable to common stockholders	$ (0.38)	$ (0.69)	$ (1.46)	$ (17.83)