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Summary of Significant Accounting Policies (Details) $ in Thousands |  | 12 Months Ended
--- | --- | ---
May 01, 2018 | Dec. 31, 2018 USD ($) item | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Summary of Significant Accounting Policies |  |  |  |
Common stock dividend declared, percentage of shares outstanding | 5.00% |  |  |
Allowance for doubtful accounts |  | $ 250 | $ 250 |
Number of states in which the Company operates | item |  | 48 |  |
Impairment of long-lived assets |  | $ 0 | 0 | $ 0
Impairment of Intangible Assets |  | $ 0 | $ 0 | $ 0
Federal statutory effective income tax rate |  | 21.00% | 35.00% | 35.00%

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