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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	$ 404	$ 330
Impairment Charges	91	150	$ 161
Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	376	329
Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	28	1
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
Level 1 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 1 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0	0
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
Level 2 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 2 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 | Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	404	330
Level 3 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	376	329
Level 3 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	28	1
Fair value on a non-recurring basis | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	77	76	97
Fair value on a non-recurring basis | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	$ 14	$ 74	$ 64