Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	$ 12,194.2
AOCI before reclassifications	9.4
Reclassifications to statements of earnings	1.4
Stockholders equity, ending balance	12,577.9
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(55.6)
AOCI before reclassifications	42.1
Reclassifications to statements of earnings	1.8
Stockholders equity, ending balance	(11.7)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(7.2)
AOCI before reclassifications	(32.7)
Stockholders equity, ending balance	(39.9)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(235.0)
Reclassifications to statements of earnings	(0.4)
Stockholders equity, ending balance	(235.4)
Total AOCI [Member]
Other Comprehensive Income Loss [Line Items]
Stockholders equity, beginning balance	(297.8)
Stockholders equity, ending balance	$ (287.0)