Business Segment, Geographic and Major Customer Information - Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information
Revenue	$ 11,770	$ 19,416
Customer Concentration Risk | Sales | Customer A | Chemistry Technologies
Segment Reporting Information
Revenue	$ 3,029	$ 7,754
Percentage of revenue by major customers (in percentage)	25.70%	39.90%
Customer Concentration Risk | Sales | Customer B | Chemistry Technologies
Segment Reporting Information
Revenue	$ 2,849	$ 3,480
Percentage of revenue by major customers (in percentage)	24.20%	17.90%