| Fair Value, Assets Measured on Recurring Basis |
The following tables summarize our assets measured at fair value on a recurring basis and the classification by level of input within the fair value hierarchy (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fair Value Measurement at Reporting Date Using | | Description | | December 31, 2025 | | Quoted Prices in Active Markets for Identical Assets
(Level 1) | | Significant Other Observable Inputs
(Level 2) | | Significant Unobservable Inputs
(Level 3) | | Cash equivalents: | | | | | | | | | | Money market funds | | $ | 27,928 | | | $ | 27,928 | | | $ | — | | | $ | — | | | U.S. government securities | | 1,623 | | | 1,623 | | | — | | | — | | | | | | | | | | | | Time deposits | | 328 | | | — | | | 328 | | | — | | | Corporate debt securities | | 1,603 | | | — | | | 1,603 | | | — | | | Total cash equivalents | | 31,482 | | | 29,551 | | | 1,931 | | | — | | | Marketable securities: | | | | | | | | | | U.S. government securities | | 21,483 | | | 21,483 | | | — | | | — | | | U.S. government agency securities | | 767 | | | 767 | | | — | | | — | | | Corporate debt securities | | 17,477 | | | — | | | 17,477 | | | — | | | Marketable equity securities | | 5,992 | | | 5,992 | | | — | | | — | | | Total marketable securities | | 45,719 | | | 28,242 | | | 17,477 | | | — | | | Restricted cash equivalents | | 2,539 | | | 2,539 | | | — | | | — | | | Other assets | | 106 | | | — | | | — | | | 106 | | | Total | | $ | 79,846 | | | $ | 60,332 | | | $ | 19,408 | | | $ | 106 | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fair Value Measurement at Reporting Date Using | | Description | | December 31, 2024 | | Quoted Prices in Active Markets for Identical Assets
(Level 1) | | Significant Other Observable Inputs
(Level 2) | | Significant Unobservable Inputs
(Level 3) | | | | | | | | | | | Cash equivalents: | | | | | | | | | | Money market funds | | $ | 36,165 | | | $ | 36,165 | | | $ | — | | | $ | — | | | U.S. government and agency securities | | 23 | | | 23 | | | — | | | — | | | Time deposits | | 369 | | | — | | | 369 | | | — | | | Corporate debt securities | | 114 | | | — | | | 114 | | | — | | | Total cash equivalents | | 36,671 | | | 36,188 | | | 483 | | | — | | | Marketable securities: | | | | | | | | | | U.S. government securities | | 14,889 | | | 14,889 | | | — | | | — | | | U.S. government agency securities | | 3,053 | | | 3,053 | | | — | | | — | | | Corporate debt securities | | 14,758 | | | — | | | 14,758 | | | — | | | Marketable equity securities | | 1,226 | | | 1,226 | | | — | | | — | | | Total marketable securities | | 33,926 | | | 19,168 | | | 14,758 | | | — | | | Restricted cash equivalents | | 1,193 | | | 1,193 | | | — | | | — | | | Other assets | | 101 | | | — | | | — | | | 101 | | | Total | | $ | 71,891 | | | $ | 56,549 | | | $ | 15,241 | | | $ | 101 | |
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| Available-for-sale Marketable Securities |
The following tables summarize our available-for-sale marketable debt securities with unrealized losses as of December 31, 2025 and 2024, aggregated by major security type and the length of time that individual securities have been in a continuous loss position (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2025 | | Less than 12 months | | 12 months or greater | | Total | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | U.S. government securities | $ | 1,491 | | | $ | (2) | | | $ | 1,570 | | | $ | (18) | | | $ | 3,061 | | | $ | (20) | | | U.S. government agency securities | 17 | | | — | | | 25 | | | — | | | 42 | | | — | | | Corporate debt securities | 1,213 | | | (1) | | | 1,534 | | | (20) | | | 2,747 | | | (21) | | | Total | $ | 2,721 | | | $ | (3) | | | $ | 3,129 | | | $ | (38) | | | $ | 5,850 | | | $ | (41) | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2024 | | Less than 12 months | | 12 months or greater | | Total | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | U.S. government securities | $ | 6,860 | | | $ | (71) | | | $ | 4,330 | | | $ | (146) | | | $ | 11,190 | | | $ | (217) | | | U.S. government agency securities | 435 | | | (2) | | | 2,083 | | | (44) | | | 2,518 | | | (46) | | | Corporate debt securities | 2,989 | | | (26) | | | 6,373 | | | (192) | | | 9,362 | | | (218) | | | Total | $ | 10,284 | | | $ | (99) | | | $ | 12,786 | | | $ | (382) | | | $ | 23,070 | | | $ | (481) | |
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