Revenue - (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue
Revenue	$ 122,965	$ 74,305	$ 241,956	$ 165,782
North America
Disaggregation of Revenue
Revenue	8,915	9,380	19,576	20,988
Asia Pacific
Disaggregation of Revenue
Revenue	106,604	49,717	203,432	112,643
Europe
Disaggregation of Revenue
Revenue	7,446	15,208	18,948	32,151
Systems
Disaggregation of Revenue
Revenue	76,815	37,224	159,152	94,316
Aftermarket
Disaggregation of Revenue
Revenue	$ 46,150	$ 37,081	$ 82,804	$ 71,466

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