Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Unrecognized Tax Benefits [Line Items]
Unrecognized tax benefits - beginning of year	$ 31.0	$ 23.7	$ 20.8
Gross additions - current year tax positions	4.6	8.7	4.4
Gross additions - prior year tax positions	8.3	2.2	0.7
Gross additions (reductions) - purchase accounting adjustments	0.1	(1.1)	1.6
Gross reductions - prior year tax positions	(2.1)	(2.5)	(3.2)
Gross reductions - settlements with taxing authorities	(3.6)		(0.6)
Impact of change in foreign exchange rates	(0.1)
Unrecognized tax benefits - end of year	$ 38.2	$ 31.0	$ 23.7