Income (Loss) Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Domestic	$ 13,363	$ (7,328)	$ (16,751)
Foreign	171,368	127,327	108,936
Income before income tax expense and equity in net loss of affiliate	$ 184,731	$ 119,999	$ 92,185