Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	$ (587,619)	$ (567,165)
Amortization	16,156	13,951
Current period change	(22,093)	28,626
Accumulated other comprehensive loss, end of period	(593,556)	(524,588)
Currency Translation Adjustments
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	57,848	28,219
Current period change	(18,316)	31,180
Accumulated other comprehensive loss, end of period	39,532	59,399
Net Actuarial Loss
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	(648,125)	(599,687)
Amortization	17,176	15,173
Current period change	(3,714)	(2,547)
Accumulated other comprehensive loss, end of period	(634,663)	(587,061)
Prior Service Credit
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	2,634	4,291
Amortization	(1,020)	(1,222)
Current period change	0	0
Accumulated other comprehensive loss, end of period	1,614	3,069
Transition Obligation
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	12	12
Amortization	0	0
Current period change	0	0
Accumulated other comprehensive loss, end of period	12	12
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	12	0
Current period change	(63)	(7)
Accumulated other comprehensive loss, end of period	$ (51)	$ (7)