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Revenue From Contracts with Customers - Disaggregate Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
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Sep. 30, 2018 | Sep. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition |  |
Total Revenues | $ 454,890 | $ 1,363,121
Graphite Electrodes - Three-to-five-year contracts |  |
Revenue, Initial Application Period Cumulative Effect Transition |  |
Total Revenues | 359,405 | 976,852
Graphite Electrodes - Short-term contracts |  |
Revenue, Initial Application Period Cumulative Effect Transition |  |
Total Revenues | 77,386 | 341,804
By-products |  |
Revenue, Initial Application Period Cumulative Effect Transition |  |
Total Revenues | $ 18,099 | $ 44,465

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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 32 -Paragraph 2A -URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045 + Details
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