Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	$ 11,271.3
AOCI before reclassifications	10.1
Reclassifications to statement of earnings	(6.2)
Stockholders Equity, Ending Balance	11,534.4
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(31.3)
AOCI before reclassifications	(4.4)
Stockholders Equity, Ending Balance	(35.7)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(177.0)
Reclassifications to statement of earnings	2.0
Stockholders Equity, Ending Balance	(175.0)
Total AOCI [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	(187.4)
Stockholders Equity, Ending Balance	(183.5)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders Equity, Beginning Balance	20.9
AOCI before reclassifications	14.5
Reclassifications to statement of earnings	(8.2)
Stockholders Equity, Ending Balance	$ 27.2