Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	$ 12,194.2
AOCI before reclassifications	(9.0)
Reclassifications to statements of earnings	8.7
Stockholders equity, ending balance	12,708.6
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(55.6)
AOCI before reclassifications	60.6
Reclassifications to statements of earnings	3.4
Stockholders equity, ending balance	8.4
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(7.2)
AOCI before reclassifications	(69.6)
Stockholders equity, ending balance	(76.8)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(235.0)
Reclassifications to statements of earnings	5.3
Stockholders equity, ending balance	(229.7)
Total AOCI [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(297.8)
Stockholders equity, ending balance	$ (298.1)