Employee Benefit Plans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Plans
Schedule of Employee Benefit Plans [Line Items]
Service cost	$ 3.1	$ 3.6
Interest cost	1.5	1.3
Expected return on assets	(1.7)	(2.1)
Gain	(0.1)
Net periodic benefit cost	2.8	2.8
Post-retirement Benefits
Schedule of Employee Benefit Plans [Line Items]
Service cost	0.5	0.6
Interest cost	1.6	1.4
Prior service cost	(0.9)	(0.9)
Net periodic benefit cost	$ 1.2	$ 1.1