Asset Retirement Obligation (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Asset retirement obligation | $ 745 | $ 701 | |
| Accretion expense | 44 | 31 | $ 0 |
| Other assets | 1,800 | 1,839 | |
| Facility Closure Trust Deposit | |||
| Other assets | $ 670 | 450 | |
| Asset Retirement Cost [Member] | |||
| Asset retirement obligation | $ 670 | ||
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- Definition Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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 assets classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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