Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (1,499)		$ (1,059)
Accumulated other comprehensive income (loss), beginning balance	(82,876)	(29,818)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	(677)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	237
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	1,866	79
Negative prior service cost (reclassified to salaries, wages and benefits)	(136)	(872)
Hedging gain (reclassified to interest expense)	(9)	(11)
Income Tax (Expense) or Benefit	3	4
Income Tax (Expense) or Benefit	(388)	292
Other comprehensive income (loss), net of tax	(6)	(7)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(440)	0
Other comprehensive income (loss), net of tax	656	(512)
Accumulated other comprehensive income (loss), ending balance	(82,220)	(30,330)
Total comprehensive income (loss)	9,765	6,221
Pension Plans [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(81,191)	(31,072)
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	1,793	(1)
Income Tax (Expense) or Benefit	(651)	0
Other comprehensive income (loss), net of tax	1,142	(1)
Accumulated other comprehensive income (loss), ending balance	(80,049)	(31,073)
Post-Retirement Plans [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(630)	1,245
Amounts reclassified from accumulated other comprehensive income:
Actuarial costs (reclassified to salaries, wages and benefits)	73	80
Negative prior service cost (reclassified to salaries, wages and benefits)	(136)	(872)
Income Tax (Expense) or Benefit	23	288
Other comprehensive income (loss), net of tax	(40)	(504)
Accumulated other comprehensive income (loss), ending balance	(670)	741
Derivative [Member]
Schedule of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), beginning balance			4	9
Amounts reclassified from accumulated other comprehensive income:
Accumulated other comprehensive income (loss), ending balance	$ (2)	$ 2	$ 4	$ 9