Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	$ 12,194.2
AOCI before reclassifications	20.8
Reclassifications to statements of earnings	0.3
Stockholders equity, ending balance	12,445.0
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(55.6)
AOCI before reclassifications	39.9
Reclassifications to statements of earnings	(0.5)
Stockholders equity, ending balance	(16.2)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(7.2)
AOCI before reclassifications	(19.1)
Stockholders equity, ending balance	(26.3)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(235.0)
Reclassifications to statements of earnings	0.8
Stockholders equity, ending balance	(234.2)
Total AOCI [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(297.8)
Stockholders equity, ending balance	$ (276.7)