Summary of Significant Accounting Policies (Details of Reclassification) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Amount reclassified out of accumulated other comprehensive loss
Prior service cost	$ 53	$ 161
Settlement expense	762	858
Amortization of actuarial loss	1,153	2,547
Total before tax	1,968	3,566
Income tax benefit	(728)	(1,209)
Amount reclassified out of accumulated other comprehensive loss	$ 1,240	$ 2,357