Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ (20.7)	$ (20.3)	$ (76.0)	$ (1.2)
Amount allocated to common stockholders (as percent)	100.00%	100.00%	100.00%	100.00%
Basic and diluted EPS
Net income (loss) allocated to common stockholders	$ (20.7)	$ (20.3)	$ (76.0)	$ (1.2)
Net income (loss) allocated to common stockholders (shares)	88.9	87.6	88.6	87.6
Basic and diluted (per share)	$ (0.23)	$ (0.23)	$ (0.86)	$ (0.01)
Securities excluded from calculation of diluted EPS (shares)	0.7	1.3	0.6	1.4

Net Income (Loss) Available to Common Stockholders, Basic and Diluted

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Percentage of net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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