Other Income, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Income and Expenses [Abstract]
Interest income	$ 753	$ 1,470	$ 1,761
Other nonoperating income	2,408	3,601	2,603
Insurance Policy Expense (Income), Net	(197)	(806)	(1,228)
Other income, net	$ 2,964	$ 4,265	$ 3,136