Earnings (Loss) Per Share - Computation of Weighted Average Shares Outstanding (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income (loss) from continuing operations	$ 14.7	$ (49.6)	$ 11.2	$ (58.5)
Net loss (income) attributable to the non-controlling interests	0.0	0.6	(0.6)	(0.7)
Net income (loss) from continuing operations attributable to common stockholders	$ 14.7	$ (49.0)	$ 10.6	$ (59.2)
Basic weighted average common shares outstanding (in shares)	257.3	288.2	262.7	288.0
Number of shares issuable upon conversion of founder preferred stock (shares)	2.0	0.0	2.0	0.0
Number of stock options, RSUs and shares issued through ESPP (shares)	0.3	0.0	0.6	0.0
Denominator adjustments for diluted EPS (in shares)	2.3	0.0	2.6	0.0
Diluted weighted average common shares outstanding (in shares)	259.6	288.2	265.3	288.0
Earnings (loss) per share from continuing operations attributable to common stockholders:
Basic (in dollars per share)	$ 0.06	$ (0.17)	$ 0.04	$ (0.21)
Diluted (in dollars per share)	$ 0.06	$ (0.17)	$ 0.04	$ (0.21)