INVESTMENTS - Financial Instruments by Significant Categories and Fair Value Measurement on a Recurring Basis (Details) - Fair Value Measurement on a Recurring Basis - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Securities
Cash equivalents:	$ 435	$ 332
Amortized Cost	475	464
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(4)	(4)
Fair Value	472	460
Cash and cash equivalents
Debt Securities
Cash equivalents:	347	243
Fair Value	0	0
Investments
Debt Securities
Cash equivalents:	0	0
Fair Value	231	226
Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	88	89
Fair Value	241	234
Asset-backed securities \| Level 2
Debt Securities
Amortized Cost	42	42
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2)	(2)
Fair Value	40	40
Asset-backed securities \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
Asset-backed securities \| Level 2 \| Investments
Debt Securities
Fair Value	40	40
Asset-backed securities \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	0	0
Corporate bonds \| Level 2
Debt Securities
Amortized Cost	130	140
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	129	139
Corporate bonds \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
Corporate bonds \| Level 2 \| Investments
Debt Securities
Fair Value	105	112
Corporate bonds \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	24	27
Agency securities \| Level 2
Debt Securities
Amortized Cost	34	33
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	33	32
Agency securities \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
Agency securities \| Level 2 \| Investments
Debt Securities
Fair Value	4	5
Agency securities \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	29	27
U.S. treasuries \| Level 2
Debt Securities
Amortized Cost	251	229
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair Value	252	229
U.S. treasuries \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
U.S. treasuries \| Level 2 \| Investments
Debt Securities
Fair Value	75	62
U.S. treasuries \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	177	167
Certificate of deposit \| Level 2
Debt Securities
Amortized Cost	11	12
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	11	12
Certificate of deposit \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
Certificate of deposit \| Level 2 \| Investments
Debt Securities
Fair Value	0	0
Certificate of deposit \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	11	12
Other debt securities \| Level 2
Debt Securities
Amortized Cost	7	8
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	7	8
Other debt securities \| Level 2 \| Cash and cash equivalents
Debt Securities
Fair Value	0	0
Other debt securities \| Level 2 \| Investments
Debt Securities
Fair Value	7	7
Other debt securities \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	0	1
Money market mutual funds \| Level 1
Debt Securities
Cash equivalents:	422	314
Money market mutual funds \| Level 1 \| Cash and cash equivalents
Debt Securities
Cash equivalents:	334	225
Money market mutual funds \| Level 1 \| Investments
Debt Securities
Cash equivalents:	0	0
Money market mutual funds \| Level 1 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	88	89
U.S. treasuries \| Level 2
Debt Securities
Cash equivalents:	13	18
U.S. treasuries \| Level 2 \| Cash and cash equivalents
Debt Securities
Cash equivalents:	13	18
U.S. treasuries \| Level 2 \| Investments
Debt Securities
Cash equivalents:	0	0
U.S. treasuries \| Level 2 \| Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	$ 0	$ 0

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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