Postretirement Benefit Plans - Changes in Fair Value of Plan Assets of Pension Plans (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Plan assets - January 1	$ 191.8
Employer contributions	71.0	30.8
Plan assets - December 31	257.0	191.8
Funded status at end of year	(343.0)	(330.1)
U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets - January 1	182.3	185.0
Actual return on plan assets	22.6	(5.8)
Employer contributions	58.3	18.2
Benefits and expenses paid	(16.1)	(15.1)
Plan assets - December 31	247.1	182.3
Funded status at end of year	(56.5)	(95.5)
International Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets - January 1	2.0	1.7
Actual return on plan assets	0.1	0.1
Employer contributions	3.0	3.2
Benefits and expenses paid	(3.1)	(3.0)
Plan assets - December 31	2.0	2.0
Funded status at end of year	(81.4)	(50.3)
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets - January 1	184.3	186.7
Actual return on plan assets	22.7	(5.7)
Employer contributions	61.3	21.4
Benefits and expenses paid	(19.2)	(18.1)
Plan assets - December 31	249.1	184.3
Funded status at end of year	$ (137.9)	$ (145.8)