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Summary of Revenue by Geographic Area (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2016
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue | $ 20,587 | $ 21,270 | $ 19,247 | $ 14,644 | $ 23,683 | $ 14,195 | $ 20,558 | $ 15,285 | $ 75,748 | $ 73,721 | $ 62,060
Asia (excluding Middle East) |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 2,143 | 7,924 | 18,745
Canada |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 15,945 | 11,318 | 3,048
Europe |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 4,743 | 3,883 | 4,219
Middle East |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 76 | 609 | 1,749
United States |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 50,522 | 47,966 | 32,317
Other |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | $ 2,319 | $ 2,021 | $ 1,982

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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 + Details
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