Segment Information - Sales By Geographic Area (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, Revenue Reconciling Item [Line Items]
Customer Revenues	$ 13,780	$ 16,883	$ 16,858	$ 33,741	$ 47,521	$ 61,793	$ 79,061
% of total						100.00%	100.00%
Americas
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 59,178	$ 72,522
% of total						95.00%	92.00%
Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 2,282	$ 4,056
% of total						4.00%	5.00%
Asia
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 333	$ 2,483
% of total						1.00%	3.00%
TS
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 55,917	$ 71,159
% of total						90.00%	90.00%
TS | Americas
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 54,177	$ 67,228
TS | Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						1,645	3,285
TS | Asia
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						95	646
High Performance Products Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 5,876	$ 7,902
% of total						10.00%	10.00%
High Performance Products Segment | Americas
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 5,001	$ 5,294
High Performance Products Segment | Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						637	771
High Performance Products Segment | Asia
Segment Reporting, Revenue Reconciling Item [Line Items]
Customer Revenues						$ 238	$ 1,837