Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Income and Expenses [Abstract]
Interest income	$ 375	$ 141
Other nonoperating income	3,431	333
Insurance policy expense	(79)	(25)
Other nonoperating expense	(10)	0
Other income, net	$ 3,717	$ 449