Changes in Cumulative Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	$ (321,044)		$ (368,986)
Other comprehensive loss before reclassifications	(8,690)	[1]
Amounts reclassified from other comprehensive loss	487	[2]
Net other comprehensive loss	(8,203)
Ending balance	(329,247)		(368,986)
Tax effect for net actuarial losses and prior service costs recognized for employee benefit plans before reclassifications	(244)
Tax effect for unrealized net losses on available-for-sale securities before reclassifications	41
Tax effect for net actuarial losses and prior service costs recognized for employee benefit plans for amounts reclassified from other comprehensive loss	(207)
Tax effect for realized gains on the sale of available-for-sale securities for amounts reclassified from other comprehensive loss	11
Foreign Currency Translation Adjustments
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	(250,942)
Other comprehensive loss before reclassifications	(8,055)
Amounts reclassified from other comprehensive loss
Net other comprehensive loss	(8,055)
Ending balance	(258,997)
Net Actuarial Losses and Prior Service Costs Recognized for Employee Benefit Plans
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	(70,611)
Other comprehensive loss before reclassifications	(570)	[1]
Amounts reclassified from other comprehensive loss	504	[2]
Net other comprehensive loss	(66)
Ending balance	(70,677)
Unrealized Net Gains (Losses) on Available-for-Sale Securities
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	509
Other comprehensive loss before reclassifications	(65)	[1]
Amounts reclassified from other comprehensive loss	(17)	[2]
Net other comprehensive loss	(82)
Ending balance	$ 427

[1] Net of taxes of $244 for net actuarial losses and prior service costs recognized for employee benefit plans and $41 for unrealized net losses on available-for-sale securities.

[2] Net of taxes of $(207) for net actuarial losses and prior service costs recognized for employee benefit plans and $11 for realized gains on the sale of available-for-sale securities.