Accumulated Other Comprehensive Loss (Rollforward of Accumulated Other comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Changes in Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		$ (229,403)	$ (181,723)	$ (221,958)	[1]	$ (179,210)
Other comprehensive income (loss) before reclassifications		(319)	4,317	(10,529)		271
Amounts reclassified from accumulated other comprehensive income		2,036	1,967	4,801		3,500
Net current period other comprehensive (loss) income		1,717	6,284	(5,728)		3,771
Ending balance		(227,686)	(175,439)	(227,686)		(175,439)
Foreign currency translation adjustments
Changes in Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(14,869)	(502)	(4,659)		3,544
Other comprehensive income (loss) before reclassifications		(319)	4,317	(10,529)		271
Amounts reclassified from accumulated other comprehensive income		0	0	0		0
Net current period other comprehensive (loss) income		(319)	4,317	(10,529)		271
Ending balance		(15,188)	3,815	(15,188)		3,815
Retirement liabilities
Changes in Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(214,534)	(181,221)	(217,299)	[2]	(182,754)	[2]
Other comprehensive income (loss) before reclassifications		0	0	0	[2]	0	[2]
Amounts reclassified from accumulated other comprehensive income		2,036	1,967	4,801	[2]	3,500	[2]
Net current period other comprehensive (loss) income	[2]	2,036	1,967	4,801		3,500
Ending balance	[2]	$ (212,498)	$ (179,254)	$ (212,498)		$ (179,254)

[1] Derived from the audited Consolidated Balance Sheet

[2] Retirement liabilities reclassified to net income are related to the amortization of actuarial losses and are included in "Selling, general, and administrative expenses" in the Company's unaudited Condensed Consolidated Statements of Income. See Note 6, "Defined Benefit Pension Plans" for additional details.