Postretirement Benefit Plans - Net Loss and Prior Service Cost that will be Amortized from Accumulated Other Comprehensive Income Loss (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 8.9
Prior service cost (credit)	(5.4)
Total	3.5
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	6.6
Prior service cost (credit)	0.6
Total	7.2
Others Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	2.3
Prior service cost (credit)	(6.0)
Total	$ (3.7)