Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (1,410)	$ (938)	$ (1,410)	$ (938)	$ (1,355)	$ (1,059)	$ 0	$ 0
Accumulated other comprehensive income (loss), beginning balance	(80,972)	(30,841)	(82,876)	(29,818)
Other comprehensive income (loss) before reclassifications:
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	(84)	(1,042)	(537)	(1,042)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	29	104	186	104
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	1,866	79	5,598	238
Negative prior service cost (reclassified to salaries, wages and benefits)	(136)	(872)	(408)	(2,616)
Hedging gain (reclassified to interest expense)	0	(10)	(50)	(32)
Income Tax (Expense) or Benefit	0	4	46	12
Income Tax (Expense) or Benefit	(599)	396	(1,652)	980
Other comprehensive income (loss), net of tax	0	(6)	(4)	(20)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(55)	(938)	(351)	(938)
Other comprehensive income (loss), net of tax		(1,449)	2,951	(2,472)
Accumulated other comprehensive income (loss), ending balance	(79,925)	(32,290)	(79,925)	(32,290)
Total comprehensive income (loss)	7,608	8,458	29,405	23,677
Pension Plans [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(78,907)	(31,073)	(81,191)	(31,072)
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	1,793	(1)	5,379	(2)
Income Tax (Expense) or Benefit	(651)	0	(1,953)	0
Other comprehensive income (loss), net of tax	1,142	(1)	3,426	(2)
Accumulated other comprehensive income (loss), ending balance	(77,765)	(31,074)	(77,765)	(31,074)
Post-Retirement Plans [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(710)	237	(630)	1,245
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	73	80	219	240
Negative prior service cost (reclassified to salaries, wages and benefits)	(136)	(872)	(408)	(2,616)
Income Tax (Expense) or Benefit	23	288	69	864
Other comprehensive income (loss), net of tax	(40)	(504)	(120)	(1,512)
Accumulated other comprehensive income (loss), ending balance	(750)	(267)	(750)	(267)
Derivative [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance	0	(5)	4	9
Amounts reclassified from accumulated other comprehensive income:
Accumulated other comprehensive income (loss), ending balance	0	$ (11)	$ 0	$ (11)
Accumulated Other Comprehensive Income (Loss) [Member]
Amounts reclassified from accumulated other comprehensive income:
Total comprehensive income (loss)	$ 1,047