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Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2019
Summary of Significant Accounting Policies  
Components of self-insurance reserves

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December 31, 

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2019

    

2018

Self-insurance reserves (undiscounted)

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$

168,397

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$

157,538

Self-insurance reserves (discounted)

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156,585

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146,718