Income Taxes (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of the beginning and ending liabilities for unrecognized tax benefits
Balance at beginning of period	$ 301	$ 425
Gross increases in current period tax positions	67	100
Gross increases in prior period tax positions	441	0
Reductions in tax positions due to lapse of statutory limitations	(22)	(12)
Settlements with taxing authorities	0	(243)
Balance at end of period	787	301
Accrued interest and penalties at end of period	0	31
Total liability for unrecognized tax benefits	$ 787	$ 301