Other Income (Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Income and Expenses [Abstract]
Interest and investment income	$ 90	$ 155	$ 148
Income tax expense	(295)	(460)	(645)
Other non-operating income	108	746	10
Total other income (expense)	$ (97)	$ 441	$ (487)