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SEGMENT INFORMATION, MAJOR CUSTOMERS AND GEOGRAPHICAL DATA Narrative (Details) - employee | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Brazil |  |  |
Revenue, Major Customer [Line Items] |  |  |
Number of employees | 181 |  |
Sales | Foreign Operations |  |  |
Revenue, Major Customer [Line Items] |  |  |
Percentage of operating revenues | 34.00% | 29.00% | 34.00%
Sales | Anadarko Petroleum Corporation |  |  |
Revenue, Major Customer [Line Items] |  |  |
Percentage of operating revenues | 28.00% | 31.00% | 28.00%
Sales | Petroleo Brasileiro S.A. |  |  |
Revenue, Major Customer [Line Items] |  |  |
Percentage of operating revenues | 21.00% | 23.00% | 22.00%
Sales | U.S. Government |  |  |
Revenue, Major Customer [Line Items] |  |  |
Percentage of operating revenues | 14.00% | 15.00% | 16.00%
Unionized Employees Concentration Risk | Number of Employees, Total |  |  |
Revenue, Major Customer [Line Items] |  |  |
Percentage of operating revenues | 26.00% |  |

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