Post-retirement Plan (Net Periodic Pension Expense) (Details) - Other Postretirement Benefit Plan [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefit earned during the period	$ 424	$ 224	$ 1,272	$ 672
Interest cost on projected benefit obligations	205	159	615	478
Amortization of prior service cost	(871)	(1,074)	(2,613)	(3,222)
Amortization of net loss	46	0	138	0
Net periodic post-retirement expense (credit)	$ (196)	$ (691)	$ (588)	$ (2,072)