NOTES PAYABLE AND LEASE OBLIGATIONS - Summary of Notes Payable (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Notes payable and lease obligations	[1]	$ 5,900	$ 5,778
Finance lease obligations		12	13
Operating lease obligations	[1]	122	0
4.00% senior notes due February 2022
Debt Instrument [Line Items]
Notes payable and lease obligations		348	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		746	746
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Notes payable and lease obligations		448	447
2.875% senior notes due October 2026
Debt Instrument [Line Items]
Notes payable and lease obligations		297	297
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable and lease obligations		220	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		540	540
.932% senior notes due January 2027
Debt Instrument [Line Items]
Notes payable and lease obligations		538	538
1.159% senior notes due October 2030
Debt Instrument [Line Items]
Notes payable and lease obligations		262	262
1.488% senior notes due October 2033
Debt Instrument [Line Items]
Notes payable and lease obligations		136	136
1.750% senior notes due October 2038
Debt Instrument [Line Items]
Notes payable and lease obligations		79	79
2.108% subordinated notes due October 2047
Debt Instrument [Line Items]
Notes payable and lease obligations		536	536
Yen-denominated loan variable interest rate due September 2021
Debt Instrument [Line Items]
Notes payable and lease obligations		45	45
Yen-denominated loan variable interest rate due September 2023
Debt Instrument [Line Items]
Notes payable and lease obligations		$ 225	$ 225

[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2019 related to leases.