Pension and Postretirement Benefits - Components of Net Periodic Benefit Expense (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.8	$ 2.2	$ 5.7	$ 6.5
Interest cost	79.3	80.0	241.2	238.9
Expected return on plan assets	(97.2)	(103.1)	(296.6)	(308.0)
Amortization of prior service (benefit) cost	(1.4)	(1.1)	(4.2)	(3.3)
Recognized net actuarial loss	38.7	49.2	116.9	147.4
Net periodic pension expense	21.2	27.2	63.0	81.5
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	57.7	56.1	173.4	168.1
Expected return on plan assets	(63.2)	(63.7)	(189.8)	(191.1)
Amortization of prior service (benefit) cost	(0.6)	(0.6)	(1.9)	(1.8)
Recognized net actuarial loss	29.0	33.1	87.0	99.5
Net periodic pension expense	22.9	24.9	68.7	74.7
International Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.8	2.2	5.7	6.5
Interest cost	21.6	23.9	67.8	70.8
Expected return on plan assets	(34.0)	(39.4)	(106.8)	(116.9)
Amortization of prior service (benefit) cost	(0.8)	(0.5)	(2.3)	(1.5)
Recognized net actuarial loss	9.7	16.1	29.9	47.9
Net periodic pension expense	(1.7)	2.3	(5.7)	6.8
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.1	0.1	0.3	0.4
Interest cost	1.6	1.7	4.8	5.1
Expected return on plan assets	(0.1)	(0.1)	(0.3)	(0.3)
Amortization of prior service (benefit) cost	0.0	0.3	0.0	0.9
Recognized net actuarial loss	0.3	0.7	0.9	2.1
Net periodic pension expense	$ 1.9	$ 2.7	$ 5.7	$ 8.2