Stockholder's Equity - Schedule of Changes in Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components Of Other Comprehensive Income Loss [Line Items]
Marketable securities, Balance at beginning of year	$ 154,169	$ 105,419	$ 186,451
Unrealized gain (loss) arising during the year	(107,057)	48,514	(71,184)
Less reclassification adjustment for amounts included in realized gain		236	(9,848)
Marketable securities, Balance at end of year	47,112	154,169	105,419
Currency translation, Balance at beginning of year	(133,816)	(135,165)	(133,041)
Arising during the year	(20,357)	1,349	6,605
Less reclassification adjustment for amounts included in gain on disposal			(8,729)
Currency translation, Balance at end of year	(154,173)	(133,816)	(135,165)
Balance at beginning of year	(35,016)	(95,253)	(4,724)
Other comprehensive income (loss)	(147,023)	60,237	(90,529)
Balance at end of year	(182,039)	(35,016)	(95,253)
Defined Benefit Pension Plans
Components Of Other Comprehensive Income Loss [Line Items]
Balance at beginning of year	(56,644)	(66,402)	(59,478)
Amortization of prior service cost and net losses included in net periodic pension cost	2,107	2,776	2,254
Net actuarial gain (loss) arising during year	(20,723)	5,952	(9,178)
Plan curtailment		1,030
Balance at end of year	(75,260)	(56,644)	(66,402)
OPEB
Components Of Other Comprehensive Income Loss [Line Items]
Balance at beginning of year	1,275	895	1,344
Amortization of prior service cost and net losses included in net periodic pension cost	(626)	(663)	(552)
Net actuarial gain (loss) arising during year	(367)	395	103
Plan amendment		648
Balance at end of year	$ 282	$ 1,275	$ 895