Components of Change in Projected Benefit Obligation and Change in Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in projected benefit obligation:
Benefit obligation, beginning balance	$ 2,306.0	$ 2,417.4
Service cost	88.6	91.3	$ 67.3
Interest cost	94.3	92.2	91.8
Benefits paid	(80.2)	(121.3)
Actuarial loss (gain)	186.4	(141.6)
Currency translation and other	(90.6)	(35.6)
Participant contributions	1.1	3.6
Projected benefit obligation, ending balance	2,505.6	2,306.0	2,417.4
Change in plan assets:
Fair value of plan assets, beginning balance	2,219.0	2,309.4
Employer contributions	185.7	62.9
Actual return on plan assets	254.5	0.3
Benefits paid	(80.2)	(121.3)
Currency translation and other	(86.0)	(35.9)
Participant contributions	1.1	3.6
Fair value of plan assets, ending balance	2,494.1	2,219.0	$ 2,309.4
Funded status, ending balance	(11.5)	(87.0)
Amounts recorded on balance sheet
Other noncurrent assets	107.2	27.2
Other liabilities	118.7	114.2
Accumulated other comprehensive loss:
Actuarial loss	410.6	386.3
Prior service cost	3.4	3.9
Net initial transition amount	$ 0.1	$ 0.2