XML 99 R80.htm IDEA: XBRL DOCUMENT v3.8.0.1
Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Parenthetical) (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]      
Gains (losses) on foreign currency transactions $ (2.9) $ 8.0 $ 2.5