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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, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2015
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue | $ 23,683 | $ 14,195 | $ 20,558 | $ 15,285 | $ 16,314 | $ 17,678 | $ 14,931 | $ 13,137 | $ 73,721 | $ 62,060 | $ 84,867
Asia (excluding Middle East) |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 7,924 | 18,745 | 8,755
Canada |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 11,318 | 3,048 | 2,298
Europe |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 3,883 | 4,219 | 13,672
Middle East |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 609 | 1,749 | 2,024
United States |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | 47,966 | 32,317 | 50,101
Other |  |  |  |  |  |  |  |  |  |  |
Schedule Of Revenues From External Customers [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  | $ 2,021 | $ 1,982 | $ 8,017

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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/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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