Business Segment, Geographic and Major Customer Information - Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information
Revenue	$ 9,165	$ 8,880	$ 20,935	$ 28,296
Customer Concentration Risk | Sales | Customer C | Chemistry Technologies
Segment Reporting Information
Revenue	$ 1,038		$ 4,067	$ 8,324
Percentage of revenue by major customers (in percentage)	11.30%		19.40%	29.40%
Customer Concentration Risk | Sales | Customer D | Chemistry Technologies
Segment Reporting Information
Revenue	$ 1,810		$ 4,660	$ 3,485
Percentage of revenue by major customers (in percentage)	19.80%		22.30%	12.30%
Customer Concentration Risk | Sales | Customer A | Chemistry Technologies
Segment Reporting Information
Revenue		$ 2,004		$ 3,536
Percentage of revenue by major customers (in percentage)		22.60%		12.50%
Customer Concentration Risk | Sales | Customer B | Chemistry Technologies
Segment Reporting Information
Revenue		$ 1,246
Percentage of revenue by major customers (in percentage)		14.00%