NOTES PAYABLE - Summary of Notes Payable (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Notes payable		$ 4,984	$ 4,971
2.65% senior notes due February 2017
Debt Instrument [Line Items]
Notes payable	[1]	650	651
2.40% senior notes due March 2020
Debt Instrument [Line Items]
Notes payable		547	546
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		696	696
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Notes payable	[2]	744	744
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Notes payable	[2]	446	445
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable	[2]	393	393
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Notes payable	[2]	444	445
5.50% subordinated notes due September 2052
Debt Instrument [Line Items]
Notes payable		486	486
2.26% yen-denominated Uridashi notes due September 2016
Debt Instrument [Line Items]
Notes payable		71	66
1.84% yen-denominated Samurai notes due July 2016
Debt Instrument [Line Items]
Notes payable		140	131
Capitalized Lease Obligations
Debt Instrument [Line Items]
Notes payable		$ 19	$ 20

[1] Principal amount plus an issuance premium that is being amortized over the life of the notes

[2] Principal amount net of an issuance discount that is being amortized over the life of the notes