Employee Benefit Plans, Schedule of Net Periodic Benefit Cost Not Yet Recognized (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unamortized net actuarial gain (loss)	$ (192)	$ 289
Unamortized net actuarial gain (loss)	(478)	475	(86)
Deferred tax benefit (expense) at 35%	67	(101)
Deferred tax benefit (expense) at 35%	(6,055)	(9,937)
Net unrecognized gain (loss) on postretirement benefit costs	(125)	188
Accumulated other comprehensive income (loss)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unamortized net actuarial gain (loss)	0
Deferred tax benefit (expense) at 35%	0
Net unrecognized gain (loss) on postretirement benefit costs	$ 0