Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income or Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (57,808)		$ (62,802)
Other comprehensive income before reclassifications	9,961		6,475
Actuarial net gain (loss) incurred in the fiscal year	32,749		(6,687)
Amounts reclassified from accumulated other comprehensive income	3,648		5,206
Net current-period other comprehensive income	46,358		4,994
Ending balance	(11,450)		(57,808)
AOCI, Pension and other postretirement benefit plans, tax	2,900		22,371		20,799
AOCI, Cumulative changes in net gain (loss) from cash flow hedges, tax	110		127		0
AOCI, Available-for-sale securities adjustment, tax					1,555
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	12,585		5,875
Other comprehensive income before reclassifications	10,171		6,710
Actuarial net gain (loss) incurred in the fiscal year	0		0
Amounts reclassified from accumulated other comprehensive income	0		0
Net current-period other comprehensive income	10,171		6,710
Ending balance	22,756		12,585
Funded status of pension plans and other postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(70,158)	[1],[2]	(67,239)	[1]
Other comprehensive income before reclassifications	0	[2]	0	[1]
Actuarial net gain (loss) incurred in the fiscal year	32,749	[2]	(6,687)	[1]
Amounts reclassified from accumulated other comprehensive income	3,412	[2]	3,768	[1]
Net current-period other comprehensive income	36,161	[2]	(2,919)	[1]
Ending balance	(33,997)	[2]	(70,158)	[1],[2]
Unrealized gain (loss) on derivative instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(235)	[3],[4]	(270)	[3]
Other comprehensive income before reclassifications	(210)	[4]	(235)	[3]
Actuarial net gain (loss) incurred in the fiscal year	0	[4]	0	[3]
Amounts reclassified from accumulated other comprehensive income	236	[4]	270	[3]
Net current-period other comprehensive income	26	[4]	35	[3]
Ending balance	(209)	[4]	(235)	[3],[4]
Unrealized gain (loss) on marketable securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(1,168)	[5]
Other comprehensive income before reclassifications			0	[5]
Actuarial net gain (loss) incurred in the fiscal year			0	[5]
Amounts reclassified from accumulated other comprehensive income			1,168	[5]
Net current-period other comprehensive income			1,168	[5]
Ending balance			$ 0	[5]

[1] Net of taxes of $22,371 and $20,799 for the periods ended December 31, 2012 and December 31, 2011, respectively.

[2] Net of taxes of $2,900 and $22,371 for the periods ended December 31, 2013 and December 31, 2012, respectively.

[3] Net of taxes of $127 and $0 for the periods ended December 31, 2012 and December 31, 2011, respectively.

[4] Net of taxes of $110 and $127 for the periods ended December 31, 2013 and December 31, 2012, respectively.

[5] Net of taxes of $1,555 for the period ended December 31, 2011.