Components of Comprehensive (Loss) Income, Net of Related Tax (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (594.6)	$ 378.4
Other comprehensive (loss) income (OCI):
Unrealized losses on derivative contracts, before tax	(6.6)	(0.2)
Unrealized losses on derivative contracts, tax	2.1	0.4
Net current period OCI, unrealized (losses) gain on derivative contracts	(4.5)	0.2
Unrealized gains on marketable debt securities, before tax	3.2	0.5
Unrealized gains on marketable debt securities, tax	(1.0)	(0.2)
Net current period OCI, unrealized gains on marketable debt securities	2.2	0.3
Pension plans, before tax	7.0	21.7
Pension plans, tax	(2.4)	(6.8)
Net current period OCI, pension plans	4.6	14.9
Foreign currency translation gains (losses)	125.5	(352.9)
Net other comprehensive income (loss)	127.8	(337.5)
Comprehensive (loss) income	$ (466.8)	$ 40.9