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Exit and Disposal Activities - Additional Information (Details) | 1 Months Ended | 3 Months Ended |
--- | --- | --- | ---
Dec. 31, 2017 USD ($) Employee | Dec. 31, 2017 USD ($) | Sep. 30, 2018 USD ($)
Restructuring Cost And Reserve [Line Items] |  |  |
Expected annualized cash savings | $ 6,000,000 |  |
Termination costs |  | $ 700,000 |
Expected further termination costs |  |  | $ 0
Outstanding liabilities |  |  | $ 0
Employee Reduction | Houston Area Workforce |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |
Reduction in number of employees | Employee | 60 |  |

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