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SIGNIFICANT ACCOUNTING POLICIES - Allowances for Doubtful Accounts And Revenue Allowance (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Allowance for Doubtful Accounts |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at January 1, | $ 24,634 | $ 22,493 | $ 26,368
Additions charged to earnings | 8,018 | 10,133 | 2,408
Deductions from reserves, net of recoveries | (8,516) | (7,992) | (6,283)
Balance at December 31, | 24,136 | 24,634 | 22,493
Revenue Allowance |  |  |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] |  |  |
Balance at January 1, | 20,115 | 16,218 | 17,947
Additions charged to earnings | 34,319 | 45,784 | 35,549
Deductions from reserves, net of recoveries | (38,430) | (41,887) | (37,278)
Balance at December 31, | $ 16,004 | $ 20,115 | $ 16,218

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- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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- Definition Amount of decrease in valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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