Amount of Accumulated Other Comprehensive Income Expected to be Recognized in Net Periodic Benefit Cost (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 5.7
Amount of AOCI expected to be recognized in net periodic benefit cost	5.7
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	1.2
Amount of AOCI expected to be recognized in net periodic benefit cost	1.2
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	6.9
Amount of AOCI expected to be recognized in net periodic benefit cost	6.9
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	(0.1)
Net actuarial loss (gain)	(0.2)
Amount of AOCI expected to be recognized in net periodic benefit cost	$ (0.3)