Fair Value of Financial Instruments (Narrative) (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Rabbi Trust \| Other Assets \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash surrender value	$ 4,404

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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