Changes in Cumulative Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	$ (370,389)		$ (349,288)
Other comprehensive (loss) income before reclassifications	(36,132)	[1]
Amounts reclassified from other comprehensive (loss) income	(6,469)	[2]
Net other comprehensive (loss) income	(42,601)
Ending balance	(412,990)		(349,288)
Tax effect for net actuarial gains and prior service costs recognized for employee benefit plans before reclassification	(7,794)
Tax effect for unrealized net gains on available-for-sale securities before reclassifications	(62)
Tax effect for net actuarial gains and prior service costs recognized for employee benefit plans for amounts reclassified from other comprehensive (loss) income	4,124
Tax effect for unrealized net gains on available-for-sale securities for amounts reclassified from other comprehensive (loss) income	12
Foreign Currency Translation Adjustments
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	(204,195)
Other comprehensive (loss) income before reclassifications	(48,421)	[1]
Amounts reclassified from other comprehensive (loss) income		[2]
Net other comprehensive (loss) income	(48,421)
Ending balance	(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	(166,595)
Other comprehensive (loss) income before reclassifications	12,190	[1]
Amounts reclassified from other comprehensive (loss) income	(6,450)	[2]
Net other comprehensive (loss) income	5,740
Ending balance	(160,855)
Unrealized Net Gains (Losses) on Available-for-Sale Securities
Changes in Net Other Comprehensive (Loss) Income [Roll Forward]
Beginning balance	401
Other comprehensive (loss) income before reclassifications	99	[1]
Amounts reclassified from other comprehensive (loss) income	(19)	[2]
Net other comprehensive (loss) income	80
Ending balance	$ 481

[1] Net of taxes of $(7,794) for net actuarial gains and prior service costs recognized for employee benefit plans and $(62) for unrealized net gains on available-for-sale securities.

[2] Net of taxes of $4,124 for net actuarial gains and prior service costs recognized for employee benefit plans and $12 for unrealized net gains on available-for-sale securities.