| TRANSFORMATION STRATEGY (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended | 
|---|---|---|
| Jun. 30, 2018 | Dec. 31, 2018 | |
| Restructuring and Related Activities [Abstract] | ||
| Transformation cost | $ 360 | |
| Other transformation related costs | $ 71 | 262 | 
| Other expenses | 98 | |
| Transformation strategy cost | $ 273 | 
| X | ||||||||||
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- Definition Transformation Strategy Cost No definition available. 
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| X | ||||||||||
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- Definition Amount of expense classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount of other expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses associated with a discontinued operation or an asset retirement obligation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- References No definition available. 
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| X | ||||||||||
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- Definition Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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