Other Post-Employment Benefits and Other Employee Benefit Plans - Accumulated Other Comprehensive Loss Expected to be Recognized as Components of Net Periodic Benefit Cost (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss	$ (11.4)
Prior service (credit)	0.1
Other Post-Employment Benefits and Other Employee Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss	0.4
Prior service (credit)	$ (0.8)