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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, 2026	Dec. 31, 2025
Debt Securities
Cash equivalents:	$ 208	$ 485
Amortized Cost	192	205
Gross Unrealized Gains	1	2
Gross Unrealized Losses	(1)	0
Fair Value	192	207
Cash and Cash Equivalents
Debt Securities
Cash equivalents:	92	96
Fair Value	0	0
Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	116	389
Fair Value	192	207
Level 2 | Corporate bonds
Debt Securities
Amortized Cost	30	34
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	30	34
Level 2 | Agency securities
Debt Securities
Amortized Cost	11	11
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	11	11
Level 2 | U.S. treasuries
Debt Securities
Amortized Cost	151	160
Gross Unrealized Gains	1	2
Gross Unrealized Losses	(1)	0
Fair Value	151	162
Level 2 | Cash and Cash Equivalents | Corporate bonds
Debt Securities
Fair Value	0	0
Level 2 | Cash and Cash Equivalents | Agency securities
Debt Securities
Fair Value	0	0
Level 2 | Cash and Cash Equivalents | U.S. treasuries
Debt Securities
Fair Value	0	0
Level 2 | Restricted Cash, Cash Equivalents and Investments | Corporate bonds
Debt Securities
Fair Value	30	34
Level 2 | Restricted Cash, Cash Equivalents and Investments | Agency securities
Debt Securities
Fair Value	11	11
Level 2 | Restricted Cash, Cash Equivalents and Investments | U.S. treasuries
Debt Securities
Fair Value	151	162
Money market mutual funds | Level 1
Debt Securities
Cash equivalents:	198	483
Money market mutual funds | Level 1 | Cash and Cash Equivalents
Debt Securities
Cash equivalents:	92	96
Money market mutual funds | Level 1 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	106	387
U.S. treasuries | Level 2
Debt Securities
Cash equivalents:	10	2
U.S. treasuries | Level 2 | Cash and Cash Equivalents
Debt Securities
Cash equivalents:	0	0
U.S. treasuries | Level 2 | Restricted Cash, Cash Equivalents and Investments
Debt Securities
Cash equivalents:	$ 10	$ 2

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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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