Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Marketable securities, Balance at beginning of period	$ 45,326	$ 70,238	$ 47,112	$ 154,169
Other comprehensive loss - unrealized losses arising during the year	(5,358)	(22,933)	(7,144)	(106,864)
Marketable securities, Balance at end of period	39,968	47,305	39,968	47,305
Currency translation, Balance at beginning of period	(167,132)	(134,330)	(154,173)	(133,816)
Other comprehensive income (loss)	1,188	(860)	(11,771)	(1,374)
Currency translation, Balance at end of period	(165,944)	(135,190)	(165,944)	(135,190)
Defined benefit pension plans/ Other postretirement benefit plans	(137)	(156)	(273)	(313)
Balance at beginning of period	(196,186)	(119,081)	(182,039)	(35,016)
Other comprehensive loss, net of tax	(3,220)	(23,431)	(17,367)	(107,496)
Balance at end of period	(199,406)	(142,512)	(199,406)	(142,512)
Defined Benefit Pension Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(74,526)	(56,107)	(75,260)	(56,644)
Defined benefit pension plans/ Other postretirement benefit plans	1,087	518	1,821	1,055
Balance at end of period	(73,439)	(55,589)	(73,439)	(55,589)
OPEB
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	146	1,118	282	1,275
Defined benefit pension plans/ Other postretirement benefit plans	(137)	(156)	(273)	(313)
Balance at end of period	$ 9	$ 962	$ 9	$ 962