FAIR VALUE MEASUREMENTS - Rollforward of Level 3 Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2020		Mar. 31, 2020		Jun. 30, 2021	Jun. 30, 2020	[1]
Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of year				$ 250	[1]	$ 200	$ 250
Unrealized gains included in accumulated other comprehensive loss	[2]					126	0
Balance, end of period		$ 250	[1]			$ 326	$ 250
Grab | Redeemable Convertible Preferred Stock | Long-term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized gain (loss) on debt securities		$ 20		$ (20)

[1] The Company recognized an unrealized loss of $20 million during the three months ended March 31, 2020 and an unrealized gain of $20 million during the three months ended June 30, 2020 related to the investment in Grab.

[2] The unrealized gains are recorded in “Accumulated other comprehensive loss” in the Consolidated Balance Sheet.