Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	$ 11,735.8
AOCI before reclassifications	(74.1)
Reclassifications to retained earnings (Note 2)	(42.9)
Reclassifications to statement of earnings	32.1
Stockholders Equity, Ending Balance	12,216.8
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	121.5
AOCI before reclassifications	(127.0)
Reclassifications to retained earnings (Note 2)	(17.4)
Stockholders Equity, Ending Balance	(22.9)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(138.2)
AOCI before reclassifications	(5.1)
Reclassifications to retained earnings (Note 2)	(21.1)
Reclassifications to statement of earnings	9.1
Stockholders Equity, Ending Balance	(155.3)
Total AOCI [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(83.2)
Stockholders Equity, Ending Balance	(168.1)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(66.5)
AOCI before reclassifications	58.0
Reclassifications to retained earnings (Note 2)	(4.4)
Reclassifications to statement of earnings	23.0
Stockholders Equity, Ending Balance	$ 10.1