Postretirement Benefit Plans - Changes in Projected Benefit Obligations of Pension and Other Employee-Related Defined Benefit Plans (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in benefit obligation
Benefit obligation – January 1	$ 532.6	$ 600.0
Service cost	6.3	9.5
Interest cost	22.9	22.9
Amendments	(54.2)	(18.9)
Actuarial (gain) loss	78.6	(55.1)
Benefits and expenses paid	(28.1)	(28.0)
Settlement	(1.6)	0
Foreign currency translation	(10.4)	2.2
Benefit obligation – December 31	546.1	532.6
U.S. Pension Plans [Member]
Change in benefit obligation
Benefit obligation – January 1	281.2	303.6
Service cost	3.2	4.9	4.8
Interest cost	13.1	12.1	12.9
Amendments	4.5	0.1
Actuarial (gain) loss	39.0	(22.9)
Benefits and expenses paid	(16.9)	(16.6)
Settlement	0	0
Foreign currency translation	0	0
Benefit obligation – December 31	324.1	281.2	303.6
International Pension Plan [Member]
Change in benefit obligation
Benefit obligation – January 1	84.8	83.4
Service cost	1.6	1.7	1.0
Interest cost	2.4	2.5	2.5
Amendments	0	0
Actuarial (gain) loss	13.7	(1.8)
Benefits and expenses paid	(3.0)	(3.2)
Settlement	(1.6)	0
Foreign currency translation	(10.4)	2.2
Benefit obligation – December 31	87.5	84.8	83.4
Other Postretirement Benefit Plan, Defined Benefit [Member]
Change in benefit obligation
Benefit obligation – January 1	166.6	213.0
Service cost	1.5	2.9	2.5
Interest cost	7.4	8.3	9.5
Amendments	(58.7)	(19.0)
Actuarial (gain) loss	25.9	(30.4)
Benefits and expenses paid	(8.2)	(8.2)
Settlement	0	0
Foreign currency translation	0	0
Benefit obligation – December 31	$ 134.5	$ 166.6	$ 213.0