Postretirement Benefit Plans - Changes in Fair Value of Plan Assets 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
Change in plan assets
Plan assets - January 1	$ 278.0	$ 257.0
Actual return on plan assets	22.5	36.8
Employer contributions	12.6	11.9
Benefits and expenses paid	(28.1)	(27.7)
Settlement	(1.6)	0
Plan assets - December 31	283.4	278.0
Funded status at end of year	(262.7)	(254.6)
U.S. Pension Plans [Member]
Change in plan assets
Plan assets - January 1	266.8	247.1
Actual return on plan assets	22.1	35.4
Employer contributions	0.9	0.9
Benefits and expenses paid	(16.9)	(16.6)
Settlement	0
Plan assets - December 31	272.9	266.8
Funded status at end of year	(51.2)	(14.4)
International Pension Plan [Member]
Change in plan assets
Plan assets - January 1	2.0	2.0
Actual return on plan assets	0.1	0.1
Employer contributions	3.5	2.8
Benefits and expenses paid	(3.0)	(2.9)
Settlement	(1.6)
Plan assets - December 31	1.0	2.0
Funded status at end of year	(86.5)	(82.8)
Other Postretirement Benefit Plan [Member]
Change in plan assets
Plan assets - January 1	9.2	7.9
Actual return on plan assets	0.3	1.3
Employer contributions	8.2	8.2
Benefits and expenses paid	(8.2)	(8.2)
Settlement	0
Plan assets - December 31	9.5	9.2
Funded status at end of year	$ (125.0)	$ (157.4)