Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale Securities	$ 25.6	$ 15.0
Term Deposits	4.2	6.8
Interest Rate Swap	0.8	0.5
Total Assets Measured at Fair Value	30.6	22.3
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for Sale Securities	25.6	15.0
Total Assets Measured at Fair Value	25.6	15.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Term Deposits	4.2	6.8
Interest Rate Swap	0.8	0.5
Total Assets Measured at Fair Value	$ 5.0	$ 7.3