BUSINESS COMBINATIONS - Pro Forma (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Combinations [Abstract]
Net revenues	$ 1,062,689	$ 1,530,524	$ 1,501,146
Income (loss) from continuing operations	(242,509)	(426,500)	(361,879)
Income (loss) from discontinued operations	0	0	1,152
Net income (loss)	$ (242,509)	$ (426,500)	$ (360,727)
Income (loss) from continuing operations per common share - basic (usd per share)	$ (1.80)	$ (3.11)	$ (2.62)
Income (loss) from discontinued operations per common share - basic (usd per share)	0	0	0.01
Income (loss) per common share - basic (usd per share)	(1.80)	(3.11)	(2.61)
Income (loss) from continuing operations per common share - diluted (usd per share)	(1.80)	(3.11)	(2.62)
Income (loss) from discontinued operations per common share - diluted (usd per share)	0	0	0.01
Net income (loss) per common share - diluted (usd per share)	$ (1.80)	$ (3.11)	$ (2.61)
Weighted shares outstanding basic (shares)	134,571	136,967	138,070
Weighted shares outstanding diluted (shares)	134,571	136,967	138,070

Business Acquisition, Pro Forma Income (Loss) From Discontinued Operations, Net Of Tax

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Business Acquisition, Pro Forma Income (Loss) From Discontinued Operations, Net Of Tax, Per Share, Basic

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Business Acquisition, Pro Forma Income (Loss) From Discontinued Operations, Net Of Tax, Per Share, Diluted

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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Per basic share amount of pro forma income from continuing operations, after tax, as if the business combination had been completed at the beginning of a period.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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Per diluted share amount of pro forma income from continuing operations, after tax, as if the business combination had been completed at the beginning of a period.

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Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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The weighted average number of shares or units and dilutive common stock or unit equivalents outstanding in the calculation of proforma diluted earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

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The weighted average number of shares (units) outstanding in the calculation of pro forma basic earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

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