FAIR VALUE MEASUREMENTS (Schedule of Unrealized Gains (Losses) Related to Available-for-Sale Investments) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,066	$ 2,011
Total Unrealized Gains	1,689	1,698
Total Unrealized Losses	(19)	(6)
Total Fair Value	3,736	3,703
Amount primarily related to deferred taxes on appreciation of investment value	540	530
Short-term investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	34	6
Total Unrealized Gains	0	0
Total Unrealized Losses	0	0
Total Fair Value	34	6
Global equity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	646	500
Total Unrealized Gains	1,524	1,609
Total Unrealized Losses	(15)	(2)
Total Fair Value	2,155	2,107
Fixed-income securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,386	1,505
Total Unrealized Gains	165	89
Total Unrealized Losses	(4)	(4)
Total Fair Value	$ 1,547	$ 1,590