Significant Changes Due To Topic 606 (Summary of the Effects of Adoption of ASC Topic 606 on the Company's unaudited Consolidated Statement of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income (loss)	$ 757	$ (655)
Accounting Standards Update 2014-09 [Member]
Net income (loss)		(655)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Net income (loss)		158
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Net income (loss)		$ (813)