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FAIR VALUE - Additional Information (Detail) - USD ($) $ in Millions | Jun. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Upper limit percentage of Level 3 assets to total invested assets | 0.02% |
Short-term debt | $ 701 | $ 300
Commercial Paper |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Short-term debt | 200 | 300
Carrying Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Carrying value of debt outstanding | 4,780 | 3,792
Fair Value |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Carrying value of debt outstanding | 5,179 | 4,004
Measured On Recurring Basis |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, fair value | 18,571 | 13,452
Unobservable Inputs (Level 3) | Measured On Recurring Basis |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, fair value | $ 4 | $ 7

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