Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ (1,378.6)
Other comprehensive income before reclassifications			39.9
Amounts reclassified from accumulated other comprehensive income			108.4
Current period other comprehensive income			148.3
Ending balance	$ (1,258.1)		(1,258.1)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(3,945.3)
Ending balance	(3,797.0)		(3,797.0)
Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(833.8)
Other comprehensive income before reclassifications			(43.1)
Amounts reclassified from accumulated other comprehensive income			0.0
Current period other comprehensive income			(43.1)
Ending balance	(876.9)		(876.9)
Postretirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(3,111.5)
Other comprehensive income before reclassifications			83.0
Amounts reclassified from accumulated other comprehensive income	36.1	$ 43.1	108.4	$ 133.9
Current period other comprehensive income			191.4
Ending balance	$ (2,920.1)		$ (2,920.1)