Income (Loss) Per Share of Common Stock - Summary of Reconciliation of Numerator and Denominator Used to Calculate Basic and Diluted Loss Per Share of Common Stock (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended
	Dec. 31, 2015	Mar. 31, 2016	Feb. 28, 2015
Numerator:
Income (loss) from continuing operations	$ 7.0	$ 5.2	$ (3.5)
(Loss) income from discontinued operations, net of income taxes	0.0	(0.1)	0.2
Net income	7.0	5.1	(3.3)
Income allocated to participating securities	(0.2)	(0.1)	0.0
Net income (loss) for basic earnings per share	6.8	5.0	(3.3)
Interest on convertible subordinated debentures	0.3	0.0	0.0
Net income (loss) for diluted earnings per share	$ 7.1	$ 5.0	$ (3.3)
Basic weighted average shares (in shares)	62.9	63.0	58.9
4 1/16% Convertible Subordinated Debentures (“4 1/16% Debentures”) (in shares)	9.4	0.0	0.0
Employee stock options and stock purchase plan (in shares)	0.2	0.0	0.0
Weighted average shares of common stock outstanding, diluted (in shares)	72.5	63.0	58.9
Basic
(Loss) income per share from continuing operations (in USD per share)	$ 0.11	$ 0.08	$ (0.06)
Income (loss) per share from discontinued operations, net of income taxes (in USD per share)	0.00	0.00	0.00
Net income (loss) (in USD per share)	0.11	0.08	(0.06)
Diluted
Income (loss) from continuing operations (in USD per share)	0.10	0.08	(0.06)
(Loss) income from discontinued operations, net of income taxes (in USD per share)	0.00	0.00	0.00
Net (loss) income (in USD per share)	$ 0.10	$ 0.08	$ (0.06)