Other Operating Income, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Operating Income, net [Abstract]
Gain on sale of operating assets	$ 113	$ 1	$ 65
Frozen defined-benefit pension plan income		1,611	336
Total other operating income, net	$ 113	$ 1,612	$ 401