Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Income and Expenses [Abstract]
Interest income	$ 147	$ 94	$ 192	$ 179
Other Nonoperating Income	1	298		247
Other nonoperating expense			(1)
Insurance policy expense	(12)	0	(24)	0
Other income, net	$ 136	$ 392	$ 167	$ 426