Changes in Accumulated Other Comprehensive Income (Loss) (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net periodic benefit cost, net of tax	$ 0.7	$ 0.6	$ 0.3
Net periodic benefit cost, tax portion	0.4	0.3	0.2
Actuarial gains losses, net of tax	5.9	(3.6)	(6.4)
Actuarial gains losses, tax portion	$ 3.6	$ 2.1	$ 3.9