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Employee Benefit Plan (Tables) | 12 Months Ended
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Dec. 31, 2017
Employee Benefit Plans [Abstract] |
Unrealized Gains (Losses) On Trading Securities Held In Rabbi Trust |
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﻿ | Year ended December 31,
﻿ | 2017 |  | 2016 |  | 2015
﻿Unrealized gains (losses) on trading securities held in rabbi trust | $ | 1,520 |  | $ | 586 |  | $ | (571)
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- Definition Tabular disclosure of unrealized gains and losses on investments. + References No definition available. + Details
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