Revenues (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($) item
Revenues [Abstract]
Revenue recognized from the contract liability balance | $	$ (8)	$ (560)	$ 500
Percentage of product and service revenues single performance obligation	99.00%	99.00%	99.00%
Percentage of self-service product line revenues performance obligation	1.00%	1.00%	1.00%
Number of performance obligations associated with self-service product line	2	2	2
Number of performance obligations in self-service product line revenue	2	2	2
Revenue performance obligation product and services description	Approximately 99% of our product and service revenues are considered a single performance obligation. Our self-service product line, which is approximately one percent of our revenue for the years ended December 31, 2020, 2019 and 2018 is made up of two performance obligations: (i) the delivery of tracer materials to a customer well site and (ii) the creation of diagnostic reports ordered by customers when we do not perform an integrated service. For these contracts, we do not allocate the transaction price as the individual performance obligations are sold at standalone prices in the customer order. The transaction prices for our self-service product line that have two performance obligations are (i) the price per unit times the quantity of tracer materials and (ii) prices charged for diagnostic reports ordered by and delivered to the customer.