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BUSINESS COMBINATIONS - Additional Information (Details) $ in Thousands | 1 Months Ended | 9 Months Ended
--- | --- | ---
Nov. 02, 2018 USD ($) business | Sep. 30, 2018 business | Sep. 30, 2017 business
Minimum |  |  |
Business Acquisition [Line Items] |  |  |
Useful life of finite lived intangible assets |  | 5 years |
Maximum |  |  |
Business Acquisition [Line Items] |  |  |
Useful life of finite lived intangible assets |  | 10 years |
Western | Solid Waste Collection |  |  |
Business Acquisition [Line Items] |  |  |
Number of transfer stations acquired |  |  | 1
Western | Collection Business |  |  |
Business Acquisition [Line Items] |  |  |
Number of transfer stations acquired |  | 3 | 2
Eastern | Collection Business |  |  |
Business Acquisition [Line Items] |  |  |
Number of transfer stations acquired |  | 1 |
Subsequent Event | Solid Waste Collection |  |  |
Business Acquisition [Line Items] |  |  |
Business combination, consideration | $ | $ 24,000 |  |
Subsequent Event | Western | Solid Waste Collection |  |  |
Business Acquisition [Line Items] |  |  |
Number of transfer stations acquired | 3 |  |
Subsequent Event | Eastern | Solid Waste Collection |  |  |
Business Acquisition [Line Items] |  |  |
Number of transfer stations acquired | 1 |  |

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