Retirement Plans - Components of Net Periodic Pension Benefit Cost and Other Changes in Plan Assets and Obligations Recognized in Other Comprehensive Earnings (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
Service cost	$ 0.6	$ 0.4	$ 0.4
Interest cost on benefit obligation	11.7	11.8	11.9
Expected return on plan assets	(17.0)	(15.2)	(14.9)
Amortization of net loss	7.9	7.2	1.6
Net periodic benefit cost (earnings)	3.2	4.2	(1.0)
Net (gain) loss incurred	(36.0)	10.6	53.8
Amortization of net loss	(7.9)	(7.2)	(1.6)
Total recognized in other comprehensive (earnings) loss	(43.9)	3.4	52.2
Total recognized in net periodic pension cost (earnings) and other comprehensive (earnings) loss	(40.7)	7.6	51.2
Amortization of net loss, Estimated	$ 2.4	$ 7.7	$ 2.3