FAIR VALUE MEASUREMENTS (Schedule of Maturities on Debt Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Total maturities of fixed-income securities	$ 3,409	$ 3,703
Fixed-income securities
Debt Securities, Available-for-sale [Line Items]
Less than 1 year	26
1–5 years	397
5–10 years	408
More than 10 years	687
Total maturities of fixed-income securities	$ 1,518	$ 1,590

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