Cumulative Amount of Unrecognized Hedge Losses Recorded in Accumulated Other Comprehensive Income (Detail) - Net Investment Hedging [Member] - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Hedge Underlying Gain Loss [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	$ 30.9	$ 20.9
Foreign Exchange Contract [Member]
Hedge Underlying Gain Loss [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	33.6	$ 20.9
Long-Term Debt [Member]
Hedge Underlying Gain Loss [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	$ (2.7)