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
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Fair Value Assets Impairment Charges Measured on Nonrecurring Basis [Domain]
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	$ 97		$ 330
Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	97		329
Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		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	97		330
Level 3 | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	97		329
Level 3 | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Fair Value	0		$ 1
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]
Impairment Charges	23	$ 49
Fair value on a non-recurring basis | Other investments
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	11	41
Fair value on a non-recurring basis | Other assets
Fair Value Assets Measured on Nonrecurring Basis [Line Items]
Impairment Charges	$ 12	$ 8