Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (1,929)	$ (4,091)	$ (1,929)	$ (4,091)	$ (1,565)	$ (1,495)	$ (5,522)	$ (5,936)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(434)	1,431	(364)	1,845
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Other comprehensive income (loss), net of Tax	(434)	1,431	(364)	1,845	4,371
Pension and Other Postretirement Plans Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,215)	(4,957)	(2,215)	(4,957)	(2,287)	(2,165)	(5,095)	(5,313)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(50)	138	72	356
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Other comprehensive income (loss), net of Tax	(50)	138	72	356
Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	286	866	286	866	722	670	(427)	(623)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(384)	1,293	(436)	1,489
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Other comprehensive income (loss), net of Tax	$ (384)	$ 1,293	$ (436)	$ 1,489