Other Long-term Liabilities (Details) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Other Liabilities Disclosure [Abstract] | ||
| Pension benefits | $ 69,914 | $ 71,443 |
| Supply contract (see Note 25) | 20,612 | 22,250 |
| Other postretirement benefits | 4,503 | 3,991 |
| Supplemental retirement plans | 11,667 | 12,055 |
| Reserve for uncertain tax positions | 4,244 | 4,149 |
| Asset retirement obligation | 4,094 | 3,700 |
| Other | 5,437 | 5,567 |
| Total | $ 120,471 | $ 123,155 |
| X | ||||||||||
- Definition Liability, Supplemental Defined Benefit Plan, Noncurrent No definition available.
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- Definition Supply Contracts, Noncurrent No definition available.
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- Definition Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as noncurrent. Excludes other postretirement benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount recognized for uncertainty in income taxes classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of liability, recognized in statement of financial position, for defined benefit other postretirement plan, classified as noncurrent. Excludes pension plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Obligations not otherwise itemized or categorized in the footnotes to the financial statements that are expected to be paid after one year (or the normal operating cycle, if longer), from the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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