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INVESTMENTS - Schedule of 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, 2025	Dec. 31, 2024
Debt Securities
Cash equivalents:	$ 226	$ 571
Amortized Cost	222	230
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(3)
Fair Value	223	227
Cash and Cash Equivalents
Debt Securities
Cash equivalents:	116	257
Fair Value	0	0
Investments
Debt Securities
Cash equivalents:	0	0
Fair Value	0	0
Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	110	314
Fair Value	223	227
Corporate bonds | Level 2
Debt Securities
Amortized Cost	34	35
Gross Unrealized Gains	0
Gross Unrealized Losses	0	0
Fair Value	34	35
Corporate bonds | Level 2 | Cash and Cash Equivalents
Debt Securities
Fair Value	0	0
Corporate bonds | Level 2 | Investments
Debt Securities
Fair Value	0
Corporate bonds | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	34	35
Agency securities | Level 2
Debt Securities
Amortized Cost	13	18
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(1)
Fair Value	13	17
Agency securities | Level 2 | Cash and Cash Equivalents
Debt Securities
Fair Value	0	0
Agency securities | Level 2 | Investments
Debt Securities
Fair Value	0
Agency securities | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	13	17
U.S. treasuries | Level 2
Debt Securities
Amortized Cost	175	176
Gross Unrealized Gains	1
Gross Unrealized Losses	0	(2)
Fair Value	176	174
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	0
U.S. treasuries | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value	176	174
Certificate of deposit | Level 2
Debt Securities
Amortized Cost		1
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		1
Certificate of deposit | Level 2 | Cash and Cash Equivalents
Debt Securities
Fair Value		0
Certificate of deposit | Level 2 | Investments
Debt Securities
Fair Value		0
Certificate of deposit | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Fair Value		1
Money market mutual funds | Level 1
Debt Securities
Cash equivalents:	226	570
Money market mutual funds | Level 1 | Cash and Cash Equivalents
Debt Securities
Cash equivalents:	116	257
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:	$ 110	313
U.S. treasuries | Level 2
Debt Securities
Cash equivalents:		1
U.S. treasuries | Level 2 | Cash and Cash Equivalents
Debt Securities
Cash equivalents:		0
U.S. treasuries | Level 2 | Investments
Debt Securities
Cash equivalents:		0
U.S. treasuries | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:		$ 1

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- Definition

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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