FAIR VALUE MEASUREMENTS (Details - Assets measured at fair value on a non-recurring basis at the time of impairment and the related impairment charges recorded during the periods presented) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	$ 89		$ 89		$ 376
Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		28
Fair value on a non-recurring basis | Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	89		89		404
Impairment Charges	0	$ 37	6	$ 60
Fair value on a non-recurring basis | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	0	37	6	48
Fair value on a non-recurring basis | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	0	$ 0	0	$ 12
Fair value on a non-recurring basis | Level 1 | Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 1 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 1 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 2 | Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 2 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 2 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		0		0
Fair value on a non-recurring basis | Level 3 | Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	89		89		404
Fair value on a non-recurring basis | Level 3 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	89		89		376
Fair value on a non-recurring basis | Level 3 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	$ 0		$ 0		$ 28