Assets Held for Sale and Impairment	9 Months Ended
Assets Held for Sale and Impairment	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Assets Held for Sale and Impairment	Assets Held for Sale and Impairment Impairment Charges Impairment charges of $15.6 million and $0.2 million were recorded during the nine months ended September 30, 2020 and September 30, 2019, respectively. Impairment charges of $0.1 million were recorded during the three months ended September 30, 2019. No impairment charges were recorded during the three months ended September 30, 2020. Assets Held for Sale During the nine months ended September 30, 2020, certain property classified as “Assets held for sale” on the condensed consolidated balance sheet located in the Rocky Mountain division was re-evaluated for impairment based on an accepted offer from a buyer that indicated fair value of the real property was lower than its net book value, and impairment charges of $0.6 million were recorded during the nine months ended September 30, 2020, which is included in “Impairment of long-lived assets” on our condensed consolidated statements of operations. During 2019, management approved plans to sell real properties located in both the Northeast and Rocky Mountain divisions. As a result, management began to actively market the properties, which were expected to sell within one year. In accordance with applicable accounting guidance, the real property was recorded at the lower of net book value or fair value less costs to sell and reclassified to “Assets held for sale” on the condensed consolidated balance sheet during the three and nine months ended September 30, 2019. As the fair value of the real property reclassified as held for sale in the Rocky Mountain and Northeast divisions was lower than its net book value, impairment charges of $0.1 million and $0.2 million were recorded during the three and nine months ended September 30, 2019, respectively, which is included in “Impairment of long-lived assets” on our condensed consolidated statements of operations. Of the impairment charges recorded during the nine months ended September 30, 2019, $0.1 million related to the Northeast division and $0.1 million related to the Rocky Mountain division. Impairment of Long-Lived Assets Long-lived assets, such as property, plant and equipment and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. During 2020, there has been a significant decline in oil prices due to the impacts of the outbreak of COVID-19 and the oil supply conflict between two major oil producing countries, which resulted in a decrease in activities by our customers. As a result of these events, we determined that there were indicators that the carrying value of our assets may not be recoverable. Our impairment review during the nine months ended September 30, 2020 concluded that the carrying values of the assets associated with the landfill in the Rocky Mountain division and trucking equipment in the Southern division were not recoverable as the carrying value exceeded our estimate of future undiscounted cash flows for these asset groups. As a result, we recorded an impairment charge of $15.0 million during the nine months ended September 30, 2020 as the carrying value exceeded fair value, which is included in “Impairment of long-lived assets” on our condensed consolidated statements of operations. The fair value of the assets associated with the landfill and trucking equipment asset groups was determined using discounted estimated future cash flows (Level 3 in the fair value hierarchy). Of the impairment charges recorded during the nine months ended September 30, 2020, $11.6 million related to the Rocky Mountain division and $3.4 million related to the Southern division.