NOTES PAYABLE AND LEASE OBLIGATIONS - Summary of Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Notes payable and lease obligations	$ 8,121	$ 7,899
Finance lease obligations	13	11
Operating lease obligations	129	143
3.625% senior notes paid May 2021
Debt Instrument [Line Items]
Notes payable and lease obligations	0	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
1.125% senior sustainability notes due March 2026
Debt Instrument [Line Items]
Notes payable and lease obligations	397	0
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	991	990
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable and lease obligations	221	221
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	112	119
.932% senior notes due January 2027
Debt Instrument [Line Items]
Notes payable and lease obligations	541	578
.500% senior notes due December 2029
Debt Instrument [Line Items]
Notes payable and lease obligations	113	121
.550% senior notes due March 2030
Debt Instrument [Line Items]
Notes payable and lease obligations	119	127
1.159% senior notes due October 2030
Debt Instrument [Line Items]
Notes payable and lease obligations	264	282
.633% senior notes due April 2031
Debt Instrument [Line Items]
Notes payable and lease obligations	269	0
.843% senior notes due December 2031
Debt Instrument [Line Items]
Notes payable and lease obligations	84	90
.750% senior notes due March 2032
Debt Instrument [Line Items]
Notes payable and lease obligations	186	198
.844% senior notes due April 2033
Debt Instrument [Line Items]
Notes payable and lease obligations	108	0
1.488% senior notes due October 2033
Debt Instrument [Line Items]
Notes payable and lease obligations	137	146
.934% senior notes due December 2034
Debt Instrument [Line Items]
Notes payable and lease obligations	88	94
.830% senior notes due March 2035
Debt Instrument [Line Items]
Notes payable and lease obligations	95	101
1.039% senior notes due April 2036
Debt Instrument [Line Items]
Notes payable and lease obligations	89	0
1.750% senior notes due October 2038
Debt Instrument [Line Items]
Notes payable and lease obligations	80	85
1.122% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable and lease obligations	57	61
1.264% senior notes due April 2041
Debt Instrument [Line Items]
Notes payable and lease obligations	89	0
2.108% subordinated notes due October 2047
Debt Instrument [Line Items]
Notes payable and lease obligations	538	575
.963% subordinated bonds due April 2049
Debt Instrument [Line Items]
Notes payable and lease obligations	270	289
1.560% senior notes due April 2051
Debt Instrument [Line Items]
Notes payable and lease obligations	179	0
Yen-denominated loan variable interest rate due September 2026
Debt Instrument [Line Items]
Notes payable and lease obligations	45	48
Yen-denominated loan variable interest rate due September 2029
Debt Instrument [Line Items]
Notes payable and lease obligations	$ 225	$ 240