1. Summary of Significant Accounting Policies (Details 4) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 34,926	$ 39,274	$ 38,847	$ 39,401	$ 34,024	$ 37,903	$ 36,164	$ 38,504	$ 152,448	$ 146,595	$ 143,487
Fluid Delivery [Member]
Revenues									70,606	65,053	60,889
Cardiovascular [Member]
Revenues									50,904	48,073	47,064
Opthalmology
Revenues									10,473	13,537	15,427
Other
Revenues									20,465	19,932	20,107
United States
Revenues									95,757	93,082	91,092
Germany
Revenues									8,898	8,172	6,396
Other Countries [Member]
Revenues									$ 47,793	$ 45,341	$ 45,999