Fair Value Measurements (Details) - USD ($) $ in Thousands |
12 Months Ended | |
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Dec. 31, 2018 |
Dec. 31, 2017 |
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| Assets and liabilities measured at fair value on a recurring basis | ||
| Marketable securities in deferred compensation plan | $ 3,868 | $ 4,616 |
| Deferred Compensation, Excluding Share-based Payments and Retirement Benefits [Member] | Trustees and Management [Member] | ||
| Assets and liabilities measured at fair value on a recurring basis | ||
| Maximum percentage of participants' compensation which is deferrable (as a percent) | 100.00% | |
| Marketable securities in deferred compensation plan | $ 3,900 | $ 4,600 |
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- Definition Represents the maximum percentage of participants' compensation that is deferrable by participants under the deferred compensation plan. No definition available.
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- Definition Carrying amount as of the balance sheet date of assets held under deferred compensation agreements. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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