NET EARNINGS (LOSS) PER SHARE - Schedule of Earning (Loss) per share (Details) - shares shares in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share Basic And Diluted [Line Items]
Basic	746,931	745,897	754,556
Dilutive potential common shares	968	0	2,271
Diluted	747,899	745,897	756,827
Stock options
Earnings Per Share Basic And Diluted [Line Items]
Dilutive potential common shares	313	0	1,310
Restricted stock units
Earnings Per Share Basic And Diluted [Line Items]
Dilutive potential common shares	403	0	566
Performance share units
Earnings Per Share Basic And Diluted [Line Items]
Dilutive potential common shares	252	0	395

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1707-109256

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Earnings per share basic and diluted.

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