FAIR VALUE MEASUREMENTS (Schedule of Unrealized Gains (Losses) Related to Available-for-Sale Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,310	$ 2,180
Total Unrealized Gains	2,118	2,033
Total Unrealized Losses	(18)	(4)
Total Fair Value	4,410	4,209
Amount primarily related to deferred taxes on appreciation of investment value	740	671
Short-term investments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	25	27
Total Unrealized Gains	0	0
Total Unrealized Losses	0	0
Total Fair Value	25	27
Global equity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	500	543
Total Unrealized Gains	2,013	1,881
Total Unrealized Losses	(7)	(1)
Total Fair Value	2,506	2,423
Fixed-income securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,785	1,610
Total Unrealized Gains	105	152
Total Unrealized Losses	(11)	(3)
Total Fair Value	$ 1,879	$ 1,759