Revenue - (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue
Revenue	$ 110,405	$ 69,453	$ 352,361	$ 235,235
North America
Disaggregation of Revenue
Revenue	9,022	7,681	28,598	28,670
Asia Pacific
Disaggregation of Revenue
Revenue	89,995	47,756	293,427	160,398
Europe
Disaggregation of Revenue
Revenue	11,388	14,016	30,336	46,167
Systems
Disaggregation of Revenue
Revenue	70,239	36,809	229,391	131,124
Aftermarket
Disaggregation of Revenue
Revenue	$ 40,166	$ 32,644	$ 122,970	$ 104,111

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration