INVESTMENTS AND FAIR VALUE MEASUREMENT - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Assets
Total held-to-maturity investments	$ 53	$ 399
U.S. Treasury securities
Assets
Total held-to-maturity investments	53	338
Corporate debt securities
Assets
Total held-to-maturity investments		51
U.S. government agency securities
Assets
Total held-to-maturity investments		10
Estimate of Fair Value Measurement
Assets
Total held-to-maturity investments	53	399
Estimate of Fair Value Measurement | U.S. Treasury securities
Assets
Total held-to-maturity investments	53	338
Estimate of Fair Value Measurement | Corporate debt securities
Assets
Total held-to-maturity investments		51
Estimate of Fair Value Measurement | U.S. government agency securities
Assets
Total held-to-maturity investments		10
Estimate of Fair Value Measurement | Level 1
Assets
Total held-to-maturity investments	53	338
Estimate of Fair Value Measurement | Level 1 | U.S. Treasury securities
Assets
Total held-to-maturity investments	53	338
Estimate of Fair Value Measurement | Level 1 | Corporate debt securities
Assets
Total held-to-maturity investments		0
Estimate of Fair Value Measurement | Level 1 | U.S. government agency securities
Assets
Total held-to-maturity investments		0
Estimate of Fair Value Measurement | Level 2
Assets
Total held-to-maturity investments	0	61
Estimate of Fair Value Measurement | Level 2 | U.S. Treasury securities
Assets
Total held-to-maturity investments	0	0
Estimate of Fair Value Measurement | Level 2 | Corporate debt securities
Assets
Total held-to-maturity investments		51
Estimate of Fair Value Measurement | Level 2 | U.S. government agency securities
Assets
Total held-to-maturity investments		10
Estimate of Fair Value Measurement | Level 3
Assets
Total held-to-maturity investments	0	0
Estimate of Fair Value Measurement | Level 3 | U.S. Treasury securities
Assets
Total held-to-maturity investments	$ 0	0
Estimate of Fair Value Measurement | Level 3 | Corporate debt securities
Assets
Total held-to-maturity investments		0
Estimate of Fair Value Measurement | Level 3 | U.S. government agency securities
Assets
Total held-to-maturity investments		$ 0