Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2019 |
Dec. 31, 2018 |
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| Property, plant and equipment, accumulated depreciation | $ 5,575 | $ 3,012 |
| Certificates of proprietary interest, par value (in dollars per share) | $ 100 | $ 100 |
| Certificates of proprietary interest, outstanding (in shares) | 0 | 0 |
| Sub-share certificates of proprietary interest, par value (in dollars per share) | $ 0.0333 | $ 0.0333 |
| Sub-share certificates of proprietary interest, outstanding (in shares) | 7,756,156 | 7,762,414 |
| 1/16th Nonparticipating Perpetual Royalty Interest | ||
| Nonparticipating perpetual royalty interest rate | 6.25% | 6.25% |
| 1/128th Nonparticipating Perpetual Royalty Interest | ||
| Nonparticipating perpetual royalty interest rate | 0.78125% | 0.78125% |
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- Definition Nonparticipating Perpetual Royalty Interest Rate No definition available.
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- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Face amount or stated value per share of common stock. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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