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Major classes of assets and liabilities held for sale (Details 5) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Current assets: |  |  |
Total current assets held for sale | $ 479 | $ 14,391 |
Deferred charges and other assets: |  |  |
Total noncurrent assets held for sale | 4,392 | 196,664 |
Liabilities |  |  |
Total current liabilities held for sale | 11,993 | 9,924 |
Exploration and production [Member] | Discontinued operations, held-for-sale or disposed by sale [Member] |  |  |
Current assets: |  |  |
Receivables, net | 479 | 355 |
Total current assets held for sale | 479 | 355 |
Deferred charges and other assets: |  |  |
Net property, plant and equipment | 1,631 | 5,507 |
Deferred income taxes | 2,637 | 91,098 |
Other | 161 | 161 |
Less allowance for impairment of assets held for sale | 0 | 938 |
Total noncurrent assets held for sale | 4,429 | 95,828 |
Total assets held for sale | 4,908 | 96,183 |
Liabilities |  |  |
Accounts payable | 30 | 141 |
Taxes payable | 10,857 | 19 | [1]
Other accrued liabilities | 2,884 | 2,358 |
Total current liabilities held for sale | 13,771 | 2,518 |
Total liabilities held for sale | $ 13,771 | $ 2,518 |
[1] | On the Company's Consolidated Balance Sheets, this amount was reclassified to prepayments and other current assets and is reflected in current assets held for sale.

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