Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Principal components on income tax expense:
Current taxes	$ 4,482	$ 3,475	$ 2,897
Deferred taxes	(23)	1,378	2,247
Income tax expense (benefit)	$ 4,459	$ 4,853	$ 5,144