Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Income and Expenses [Abstract]
Interest Income	$ 3,336	$ 3,332
Other nonoperating income	164	33
Insurance policy expense	(640)	(1,403)
Other income, net	$ 2,860	$ 1,962