Schedule of Controlling and Non-Controlling Interest (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Noncontrolling Interest [Line Items]
Balance at beginning of period	$ 4,112.3		$ 3,952.4	$ 3,926.4	$ 3,468.1
Total Comprehensive Income:
Net income (loss)	88.2		135.5	358.6	417.4
Foreign currency translation	57.9		(2.1)	231.9	36.5
Net change in cash flow hedges	(3.9)		1.2	(10.5)	3.9
Defined benefit pension plan	1.3		0.8	3.8	2.2
Comprehensive income (loss)	143.5		135.4	583.8	460.0
Common Stock incentives	5.4		2.7	13.6	11.6
Cash dividends declared	(51.8)		(51.2)	(157.4)	(153.5)
Repurchased shares		$ (157.0)		(157.0)
Dividends paid to non-controlling interest on subsidiary shares					(1.7)
Investment in subsidiary by non-controlling interest			(2.3)		252.5
Balance at end of period	4,209.4	4,112.3	4,037.0	4,209.4	4,037.0
Controlling
Noncontrolling Interest [Line Items]
Balance at beginning of period	3,859.7		3,676.8	3,677.2	3,455.6
Total Comprehensive Income:
Net income (loss)	90.8		137.8	364.5	419.4
Foreign currency translation	57.1		(5.4)	224.4	23.5
Net change in cash flow hedges	(3.9)		1.2	(10.5)	3.9
Defined benefit pension plan	1.3		0.8	3.8	2.2
Comprehensive income (loss)	145.3		134.4	582.2	449.0
Common Stock incentives	5.4		2.7	13.6	11.6
Cash dividends declared	(51.8)		(51.2)	(157.4)	(153.5)
Repurchased shares				(157.0)
Balance at end of period	3,958.6	3,859.7	3,762.7	3,958.6	3,762.7
Noncontrolling Interest
Noncontrolling Interest [Line Items]
Balance at beginning of period	252.6		275.6	249.2	12.5
Total Comprehensive Income:
Net income (loss)	(2.6)		(2.3)	(5.9)	(2.0)
Foreign currency translation	0.8		3.3	7.5	13.0
Comprehensive income (loss)	(1.8)		1.0	1.6	11.0
Dividends paid to non-controlling interest on subsidiary shares					(1.7)
Investment in subsidiary by non-controlling interest			(2.3)		252.5
Balance at end of period	$ 250.8	$ 252.6	$ 274.3	$ 250.8	$ 274.3