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GOODWILL AND INTANGIBLE ASSETS - Schedule of Activity and Balances Related to Goodwill by Reporting Segment (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | $ 185,819 | $ 162,734
Acquisitions | 9,082 | 25,704
Other |  | (2,619)
Goodwill, ending balance | 194,901 | 185,819
Eastern |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 30,720 | 28,154
Acquisitions | 153 | 2,566
Other |  | 0
Goodwill, ending balance | 30,873 | 30,720
Western |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 141,055 | 120,536
Acquisitions | 8,929 | 23,138
Other |  | (2,619)
Goodwill, ending balance | 149,984 | 141,055
Resource Solutions |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 14,044 | 14,044
Acquisitions | 0 | 0
Other |  | 0
Goodwill, ending balance | $ 14,044 | $ 14,044

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)(1)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=120320667&loc=SL49117168-202975 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 + Details
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- Definition Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 + Details
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