Accumulated Other Comprehensive Income (Loss) Changes in Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance April 1,	$ (140,084)	$ (164,309)	$ (140,363)	$ (166,814)
Other comprehensive (loss) income before reclassifications	2,789	(2,495)	315	(4,022)
Amounts reclassified from accumulated other comprehensive income (net of tax)	2,647	4,326	5,400	8,358
Net current-period other comprehensive (loss) income	5,436	1,831	5,715	4,336
Ending balance June 30,	(134,648)	(162,478)	(134,648)	(162,478)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance April 1,	4,179	10,513	6,653	12,040
Other comprehensive (loss) income before reclassifications	2,789	(2,495)	315	(4,022)
Amounts reclassified from accumulated other comprehensive income (net of tax)	0	0	0	0
Net current-period other comprehensive (loss) income	2,789	(2,495)	315	(4,022)
Ending balance June 30,	6,968	8,018	6,968	8,018
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance April 1,	(144,263)	(174,822)	(147,016)	(178,854)
Other comprehensive (loss) income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (net of tax)	2,647	4,326	5,400	8,358
Net current-period other comprehensive (loss) income	2,647	4,326	5,400	8,358
Ending balance June 30,	$ (141,616)	$ (170,496)	$ (141,616)	$ (170,496)