Stockholders' Equity (Deficit), Accumulated Other Comprehensive Income (Loss) and Redeemable Noncontrolling Interest - Change in Stockholders' Equity (Deficit) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Beginning Balance	$ (49.3)
Beginning Balance, shares	37,345,117
Net income	$ 14.8	$ 13.5
Net income	15.0
Foreign currency translation	0.7
Gain on intra-entity foreign currency transactions	0.4
Changes in defined benefit pension and other post-retirement benefit plans, net of tax	0.2
Stock-based compensation expense	0.3
Ending Balance	$ (32.7)
Ending Balance, shares	37,345,117
Common Stock [Member]
Beginning Balance	$ 0.4
Beginning Balance, shares	37,345,000
Ending Balance	$ 0.4
Ending Balance, shares	37,345,000
Treasury Stock [Member]
Beginning Balance	$ (6.6)
Beginning Balance, shares	213,000
Ending Balance	$ (6.6)
Ending Balance, shares	213,000
Capital in Excess of Par Value [Member]
Beginning Balance	$ 375.4
Stock-based compensation expense	0.3
Ending Balance	375.7
Accumulated Deficit [Member]
Beginning Balance	(112.2)
Net income	14.8
Ending Balance	(97.4)
Foreign Currency Translation [Member]
Beginning Balance	(50.2)
Foreign currency translation	0.4
Gain on intra-entity foreign currency transactions	0.4
Ending Balance	(49.4)
Benefit Plan Liabilities [Member]
Beginning Balance	(258.7)
Changes in defined benefit pension and other post-retirement benefit plans, net of tax	0.2
Ending Balance	(258.5)
Available-For-Sale Investments [Member]
Beginning Balance	1.1
Ending Balance	1.1
Non-controlling Interest [Member]
Beginning Balance	1.5
Net income	0.2
Foreign currency translation	0.3
Ending Balance	$ 2.0