Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss - Reclassifications out of Accumulated Comprehensive Loss (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Amount reclassified from accumulated other comprehensive loss
Prior service cost	$ (19)	$ 40
Settlement expense	740
Amortization of actuarial loss	466	532
Total before tax	1,187	572
Income tax benefit	(431)	(210)
Amount reclassified out of accumulated other comprehensive loss	$ 756	$ 362