Profit Sharing, Retirement Savings Plans and Defined Benefit Pension Plans -Activity in Plan Asset Measured Using Level 3 Inputs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	$ 771.8	$ 760.3
Foreign exchange gain (loss)	44.6	(55.4)
Fair value of plan assets at end of period	776.2	771.8
Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	100.7
Fair value of plan assets at end of period	89.5	100.7
U.S. and International | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	100.7	79.5
Gains on assets still held at end of year	2.3	4.8
Purchases, sales, issuance, and settlements	1.3	2.7
Transfers in and/or out of Level 3	(21.2)	22.9
Foreign exchange gain (loss)	6.4	(9.2)
Fair value of plan assets at end of period	$ 89.5	$ 100.7