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Segment Information - Major customers (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2020	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Customer Revenues	$ 13,780	$ 16,883	$ 16,858	$ 33,741	$ 47,521	$ 61,793	$ 79,061
Accounts Receivable \| Customer Concentration Risk
Segment Reporting Information [Line Items]
% of Total Revenues						10.00%
Customer A \| Sales Revenue, Net [Member] \| Customer Concentration Risk
Segment Reporting Information [Line Items]
Customer Revenues						$ 6,485	$ 10,186
% of Total Revenues						10.00%	13.00%
Customer A \| Accounts Receivable \| Customer Concentration Risk
Segment Reporting Information [Line Items]
Accounts receivable, gross						$ 4,700	$ 7,400
% of Total Revenues						28.00%	36.00%