Income Taxes (Schedule of Noncurrent Deferred Taxes and Other Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred income taxes	$ 9,573	$ 11,188
Other liabilities	1,418	1,201
Total noncurrent deferred taxes and other liabilities	$ 10,991	$ 12,389