NOTES PAYABLE AND LEASE OBLIGATIONS - Summary of Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Notes payable and lease obligations	$ 7,771	$ 6,569
Finance lease obligations	11	12
Operating lease obligations	142	149
4.00% senior notes paid January 2020
Debt Instrument [Line Items]
Notes payable and lease obligations	0	348
3.625% senior notes due June 2023
Debt Instrument [Line Items]
Notes payable and lease obligations	698	698
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Notes payable and lease obligations	747	747
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Notes payable and lease obligations	448	448
2.875% senior notes due October 2026
Debt Instrument [Line Items]
Notes payable and lease obligations	298	298
3.60% senior notes due April 2030
Debt Instrument [Line Items]
Notes payable and lease obligations	990	0
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable and lease obligations	221	220
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Notes payable and lease obligations	254	254
4.00% senior notes due October 2046
Debt Instrument [Line Items]
Notes payable and lease obligations	394	394
4.750% senior notes due January 2049
Debt Instrument [Line Items]
Notes payable and lease obligations	541	541
.300% senior notes due September 2025
Debt Instrument [Line Items]
Notes payable and lease obligations	114	0
.932% senior notes due January 2027
Debt Instrument [Line Items]
Notes payable and lease obligations	555	545
.500% senior noted due December 2029
Debt Instrument [Line Items]
Notes payable and lease obligations	116	114
.550% senior notes due March 2030
Debt Instrument [Line Items]
Notes payable and lease obligations	122	0
1.159% senior notes due October 2030
Debt Instrument [Line Items]
Notes payable and lease obligations	271	266
.843% senior notes due December 2031
Debt Instrument [Line Items]
Notes payable and lease obligations	86	84
.750% senior notes due March 2032
Debt Instrument [Line Items]
Notes payable and lease obligations	191	0
1.488% senior notes due October 2033
Debt Instrument [Line Items]
Notes payable and lease obligations	140	138
.934% senior notes due December 2034
Debt Instrument [Line Items]
Notes payable and lease obligations	90	88
.830% senior notes due March 2035
Debt Instrument [Line Items]
Notes payable and lease obligations	97	0
1.750% senior notes due October 2038
Debt Instrument [Line Items]
Notes payable and lease obligations	82	81
1.122% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable and lease obligations	58	57
2.108% subordinated notes due October 2047
Debt Instrument [Line Items]
Notes payable and lease obligations	552	543
.963% subordinate bond due April 2049
Debt Instrument [Line Items]
Notes payable and lease obligations	277	272
Yen-denominated loan variable interest rate due September 2026
Debt Instrument [Line Items]
Notes payable and lease obligations	46	45
Yen-denominated loan variable interest rate due September 2029
Debt Instrument [Line Items]
Notes payable and lease obligations	$ 230	$ 227