Shareholders' Equity, Stock Plans and Preferred Stock - Schedule of Weighted Average Grant Date Fair Value and Total Intrinsic Value of Exercises (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average grant date fair value (in dollars per share)	$ 3.05	$ 0.00	$ 0.00
Total intrinsic value of exercises	$ 115	$ 2	$ 3