Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Comprehensive Income
Net income (loss)	$ 6,420	$ (8,173)	$ 13,902	$ 6,804	$ 13,370
Other comprehensive income (loss):
Adjustment to pension liability	930	1,672	2,691	5,015
Tax expense	(372)	(669)	(1,076)	(2,006)
Adjustment to pension liability, net of tax	558	1,003	1,615	3,009
Foreign currency translation adjustments	(1,348)	1,056	(742)	(663)
Total other comprehensive income (loss), net of tax	(790)	2,059	873	2,346
Comprehensive income (loss)	5,630	(6,114)	14,775	9,150
Accumulated other comprehensive income
Balance at beginning of period			(28,118)	(49,734)	(49,734)
Other comprehensive income, net of tax, before reclassifications			(742)	(663)
Amounts reclassified from accumulated other comprehensive income, net of tax			1,615	3,009
Net current period other comprehensive income (loss), net of tax			873	2,346	21,616
Balance at end of period	(27,245)	(47,388)	(27,245)	(47,388)	(28,118)
Accumulated Defined Benefit Plans Adjustment
Accumulated other comprehensive income
Balance at beginning of period			(32,279)	(54,431)	(54,431)
Amounts reclassified from accumulated other comprehensive income, net of tax			1,615	3,009
Net current period other comprehensive income (loss), net of tax			1,615	3,009
Balance at end of period	(30,664)	(51,422)	(30,664)	(51,422)
Accumulated Translation Adjustment
Accumulated other comprehensive income
Balance at beginning of period			4,161	4,697	4,697
Other comprehensive income, net of tax, before reclassifications			(742)	(663)
Net current period other comprehensive income (loss), net of tax			(742)	(663)
Balance at end of period	$ 3,419	$ 4,034	$ 3,419	$ 4,034