Financial Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short Term Investments- Available for Sale Securities	$ 214.3	$ 149.8
Term Deposits	367.8	340.5
Fair Value of Foreign Exchange Forward Contracts	0.1
Total Assets Measured at Fair Value	582.2	490.3
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short Term Investments- Available for Sale Securities	214.3	149.8
Total Assets Measured at Fair Value	214.3	149.8
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Term Deposits	367.8	340.5
Fair Value of Foreign Exchange Forward Contracts	0.1
Total Assets Measured at Fair Value	$ 367.9	$ 340.5