AVAILABLE-FOR-SALE DEBT SECURITIES - Summary of Available-for-Sale Debt Securities by Contractual Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Amortized Cost
Within one year	$ 1,687
After one year through five years	814
After five years	22
Amortized Cost	2,523	$ 2,023
Fair Value
Within one year	1,687
After one year through five years	814
After five years	22
Total	$ 2,523	$ 2,026

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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