Employee Benefits Plans (Details) - Amount recognized in accumulated other comprehensive income (loss) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension Plan [Member]
Employee Benefits Plans (Details) - Amount recognized in accumulated other comprehensive income (loss) [Line Items]
Net loss (gain)	$ 2,934	$ 2,006
Prior service cost (credit)
Total	2,934	2,006
Other Postretirement Benefit Plan [Member]
Employee Benefits Plans (Details) - Amount recognized in accumulated other comprehensive income (loss) [Line Items]
Net loss (gain)	(152)	(167)
Prior service cost (credit)	(92)	(246)
Total	$ (244)	$ (413)