NOTES PAYABLE - Summary of Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Notes payable	$ 5,315	$ 5,289
2.40% senior notes due March 2020
Debt Instrument [Line Items]
Notes payable	549	548
4.00% senior notes due February 2022
Debt Instrument [Line Items]
Notes payable	348	348
3.625% senior notes due June 2023
Debt Instrument [Line Items]
Notes payable	697	697
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Notes payable	746	745
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Notes payable	446	446
2.875% senior notes due October 2026
Debt Instrument [Line Items]
Notes payable	297	297
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable	220	220
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Notes payable	254	254
4.00% senior notes due October 2046
Debt Instrument [Line Items]
Notes payable	394	394
.932% senior notes due January 2027
Debt Instrument [Line Items]
Notes payable	540	528
2.108% subordinated notes due October 2047
Debt Instrument [Line Items]
Notes payable	538	526
Yen-denominated loan variable interest rate due September 2021
Debt Instrument [Line Items]
Notes payable	45	44
Yen-denominated loan variable interest rate due September 2023
Debt Instrument [Line Items]
Notes payable	225	220
Capitalized lease obligations
Debt Instrument [Line Items]
Notes payable	$ 16	$ 22