Accumulated Other Comprehensive Income (Loss) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (3,945.3)
Other comprehensive income before reclassifications	20.2
Amounts reclassified from accumulated other comprehensive income	35.8
Current period other comprehensive income	56.0
Ending balance	(3,889.3)
Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(833.8)
Other comprehensive income before reclassifications	12.7
Current period other comprehensive income	12.7
Ending balance	(821.1)
Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,111.5)
Other comprehensive income before reclassifications	7.5
Amounts reclassified from accumulated other comprehensive income	35.8
Current period other comprehensive income	43.3
Ending balance	$ (3,068.2)