Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period			$ (162,258)
Other comprehensive income (loss) before reclassifications			(6,941)
Amounts reclassified from accumulated other comprehensive income (loss)			10,370
Total other comprehensive income (loss)	(18,695)	19,219	3,429	12,741
Balance at the end of the period	(158,829)		(158,829)
Pension and other postretirement plans
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period			(165,150)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			9,994
Total other comprehensive income (loss)			9,994
Balance at the end of the period	(155,156)		(155,156)
Unrealized gain/(loss) on hedges
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period			(1,679)
Other comprehensive income (loss) before reclassifications			1,303
Amounts reclassified from accumulated other comprehensive income (loss)			376
Total other comprehensive income (loss)			1,679
Balance at the end of the period	0		0
Foreign currency translation adjustment
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period			4,571
Other comprehensive income (loss) before reclassifications			(8,244)
Total other comprehensive income (loss)			(8,244)
Balance at the end of the period	$ (3,673)		$ (3,673)