| Discontinued Operations, Supplemental Income Statement Disclosures [Table Text Block] |
The following is a reconciliation of the major classes of line items included in “(Loss) income from discontinued operations, net of tax” on the consolidated statements of (loss) income: | | | | | | | | | | | | | | Year Ended December 31, | | 2019 | | 2018 | | 2017 | | (Thousands of Dollars) | Revenues | $ | 248,981 |
| | $ | 441,495 |
| | $ | 369,247 |
| Costs and expenses: | | | | | | Cost of revenues | 220,595 |
| | 407,256 |
| | 318,532 |
| Impairment losses | 336,838 |
| | — |
| | — |
| General and administrative expenses (excluding depreciation and amortization expense) | 1,231 |
| | 6,133 |
| | 4,684 |
| Other depreciation and amortization expense | — |
| | 271 |
| | 263 |
| Total costs and expenses | 558,664 |
| | 413,660 |
| | 323,479 |
| Operating (loss) income | (309,683 | ) | | 27,835 |
| | 45,768 |
| Interest income (expense), net | 32 |
| | (1,839 | ) | | (1,309 | ) | Other (expense) income, net | (2,775 | ) | | 34,674 |
| | (5,226 | ) | (Loss) income from discontinued operations before income tax expense | (312,426 | ) | | 60,670 |
| | 39,233 |
| Income tax expense | 101 |
| | 1,251 |
| | 2,164 |
| (Loss) income from discontinued operations, net of tax | $ | (312,527 | ) | | $ | 59,419 |
| | $ | 37,069 |
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| Discontinued Operations, Selected Cash Flow Information [Table Text Block] |
The following table presents selected cash flow information associated with our discontinued operations: | | | | | | | | | | | | | | Year Ended December 31, | | 2019 | | 2018 | | 2017 | | (Thousands of Dollars) | Capital expenditures | $ | (27,954 | ) | | $ | (114,811 | ) | | $ | (153,785 | ) | | | | | | | Significant noncash operating activities and other adjustments: | | | | | | Depreciation and amortization expense | $ | 8,536 |
| | $ | 41,982 |
| | $ | 36,040 |
| Asset impairment losses | $ | 305,715 |
| | $ | — |
| | $ | — |
| Goodwill impairment loss | $ | 31,123 |
| | $ | — |
| | $ | — |
| Loss from sale of the St. Eustatius Operations | $ | 3,942 |
| | $ | — |
| | $ | — |
| Loss from sale of the European Operations | $ | — |
| | $ | 43,366 |
| | $ | — |
| Gain from insurance recoveries | $ | — |
| | $ | (78,756 | ) | | $ | — |
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| Disposal Groups, Including Discontinued Operations [Table Text Block] |
The following is a reconciliation of the carrying amounts of the major classes of assets and liabilities included in “Assets held for sale” and “Liabilities held for sale” on the consolidated balance sheet: | | | | | | December 31, 2018 | | (Thousands of Dollars) | Total current assets | $ | 54,404 |
| Property, plant and equipment, net | 513,820 |
| Goodwill | 31,123 |
| Assets held for sale | $ | 599,347 |
| | | Current liabilities | $ | 69,834 |
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