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Fair Value Disclosure (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Jan. 01, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
(Gain) loss on equity securities | $ (1,545) | $ 316 |
Long-term debt fair value |  | 10,400 |
Long-term Debt | 24,300 | 10,600 |
Revolving Credit Agreements |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Long-term debt fair value | 24,300 |  |
Level 1 | Fair Value, Measurements, Recurring | Bellaire |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
(Gain) loss on equity securities | $ (1,500) | $ 300 |
Accounting Standards Update 2016-01 |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Cumulative effect of new accounting principles on retained earnings |  |  | $ 0
Accounting Standards Update 2016-01 | Retained Earnings |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Cumulative effect of new accounting principles on retained earnings |  |  | $ 2,727

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