Employee Benefit Plans - Schedule of Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension Plans
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Net actuarial gain (loss)	$ 19.8	$ (66.7)	$ (30.1)
Amortization of unrecognized prior service cost (credit)	1.1	1.1	1.2
Amortization of unrecognized prior service cost net transition obligations	0.4	0.4	0.5
Amortization of unrecognized net actuarial gain/loss	14.2	9.7	8.2
Total	42.6	(55.5)	(20.2)
OPEB
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Net actuarial gain (loss)	2.2	(0.4)	(0.9)
Amortization of unrecognized net actuarial gain/loss	(2.4)	(1.8)	(2.3)
Total	4.3	(2.2)	(3.2)
Plan amendments/curtailment	$ 4.5