Changes in Cumulative Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	$ (321,044)		$ (370,389)
Other comprehensive income (loss) before reclassifications	4,558	[1]	(49,499)	[1]
Amounts reclassified from other comprehensive income (loss)	970	[2]	6,898	[2]
Net other comprehensive loss	5,528		(42,601)
Ending balance	(315,516)		(412,990)
Tax effect for net actuarial losses and prior service costs recognized for employee benefit plans before reclassifications	244		534
Tax effect for unrealized net gains on available-for-sale securities before reclassifications	(324)		(62)
Tax effect for net actuarial losses and prior service costs recognized for employee benefit plans for amounts reclassified from other comprehensive loss	(417)		(4,001)
Tax effect for realized gains on the sale of available-for-sale securities for amounts reclassified from other comprehensive loss	28		(12)
Foreign Currency Translation Adjustments
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	(250,942)		(204,195)
Other comprehensive income (loss) before reclassifications	4,612		(48,421)
Amounts reclassified from other comprehensive income (loss)
Net other comprehensive loss	4,612		(48,421)
Ending balance	(246,330)		(252,616)
Net Actuarial (Losses) Gains and Prior Service Costs Recognized for Employee Benefit Plans
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	(70,611)		(166,595)
Other comprehensive income (loss) before reclassifications	(570)	[1]	(1,177)	[1]
Amounts reclassified from other comprehensive income (loss)	1,015	[2]	6,917	[2]
Net other comprehensive loss	445		5,740
Ending balance	(70,166)		(160,855)
Unrealized Net Gains (Losses) on Available-for-Sale Securities
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	509		401
Other comprehensive income (loss) before reclassifications	516	[1]	99	[1]
Amounts reclassified from other comprehensive income (loss)	(45)	[2]	(19)	[2]
Net other comprehensive loss	471		80
Ending balance	$ 980		$ 481

[1] Net of taxes of $244 for net actuarial losses and prior service costs recognized for employee benefit plans and $(324) for unrealized net gains on available-for-sale securities.

[2] Net of taxes of $(417) for net actuarial losses and prior service costs recognized for employee benefit plans and $28 for realized gains on the sale of available-for-sale securities.