Shareholders' Equity Changes in Accumulated Other Comprehensive Income (Loss) Balances (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2016	$ (83,837)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(823)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	13,416	$ 9,866
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	14,595
Balance as of March 31, 2017	(70,065)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2016	(84,133)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	13,416
Balance as of March 31, 2017	(70,717)
Cash Flow Hedging | Foreign Exchange Contract
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2016	296
Reclassification to the income statement	(823)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	1,179
Balance as of March 31, 2017	$ 652