Schedule of Unrecognized Tax Benefit Reconciliation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits [Line Items]
Beginning balance	$ 68,510	$ 50,240
Additions based on tax positions related to the current year	20	22,480
Additions based on tax positions for prior years	6,790	0
Reductions for tax positions of prior years	(420)	(3,080)
Foreign currency translation effect	3,040	(1,130)
Ending balance	77,940	68,510
Income taxes paid, see below	(44,030)	(41,410)
Amounts, net of income taxes paid	$ 33,910	$ 27,100