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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Landfill Accounting (Detail) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 USD ($) Agreement | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Property, Plant and Equipment [Line Items] |  |  |
Capitalized interest | $ 140 | $ 295 | $ 273
Closure and post-closure costs incurrence period | 30 years |  |
Estimate of inflation rate (as a percent) | 1.50% |  |
Accretion expense | $ 5,556 | 4,401 |
Number of operation and management agreements entered into | Agreement | 4 |  |
Closure And Post Closure Costs |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Accretion expense | $ 5,556 | 4,401 | $ 3,606
Surety bond | 201,177 | 164,893 |
Letters of credit | $ 0 | $ 0 |
Minimum |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Rate of asset retirement obligation (as a percent) | 8.70% |  |
Maximum |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Rate of asset retirement obligation (as a percent) | 9.80% |  |

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