Employee Benefit Plans (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Amounts recognized in the consolidated balance sheets
Accrued benefit liability—long term	$ (8,544)	$ (4,718)
Pension Benefits [Member]
Amounts recognized in the consolidated balance sheets
Accrued benefit liability—short term	(112)	(113)
Accrued benefit liability—long term	(8,470)	(4,647)
Net liability recognized at December 31	(8,582)	(4,760)
Net actuarial (loss) gain	(8,902)	(4,356)
Net prior service (cost) credit	(25)	(34)
Accumulated other comprehensive (loss) income pre-tax at December 31	(8,927)	(4,390)
Postretirement Benefits [Member]
Amounts recognized in the consolidated balance sheets
Accrued benefit liability—short term	(4)	(4)
Accrued benefit liability—long term	(73)	(71)
Net liability recognized at December 31	(77)	(75)
Net actuarial (loss) gain	681	735
Net prior service (cost) credit	29	31
Accumulated other comprehensive (loss) income pre-tax at December 31	$ 710	$ 766