Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Supplementary Information [Line Items]
Stock-based compensation (income)/expense	$ (0.3)	$ 5.4	$ 40.7	$ 49.9
Interest income	1.6	1.3	4.4	4.2
Venezuela foreign exchange-related charges	3.3		16.9	29.0
Venezuela
Supplementary Information [Line Items]
Foreign currency exchange for remeasuring Venezuela financial statements	6.30		6.30
Net monetary assets	$ 127		$ 127
Venezuela | SICAD
Supplementary Information [Line Items]
Foreign currency exchange rate			12.0
Venezuela | SICAD-II
Supplementary Information [Line Items]
Foreign currency exchange rate			50.0