Summary of Income Tax Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred income tax expense (benefit):
Total deferred income tax expense (benefit)	$ (2.1)	$ (5.1)
Total income tax benefit	(9.1)	(8.4)	$ (2.3)
Continuing Operations
Current income tax expense (benefit):
Federal	(13.9)	(3.1)	(2.4)
State	0.4	(0.7)	(0.5)
Foreign	6.5
Total current income tax benefit	(7.0)	(3.8)	(2.9)
Deferred income tax expense (benefit):
Federal	1.3	(4.6)	0.5
State	(0.1)		0.1
Foreign	(3.3)
Total deferred income tax expense (benefit)	(2.1)	(4.6)	0.6
Total income tax benefit	$ (9.1)	$ (8.4)	$ (2.3)