Income taxes - components of provision for income taxes from continuing operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal, Current	$ (4,700)	$ 12,348	$ (2,996)
State, Current	2,377	1,912	1,736
Foreign, Current	53,151	30,748	36,422
Federal, Deferred	(37,504)	(6,593)	(9,565)
State, Deferred	(3,258)	3,435	(1,825)
Foreign, Deferred	(2,228)	(13,200)	(225)
Provision for income taxes from continuing operations	$ 7,838	$ 28,650	$ 23,547