Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Jul. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	$ 6,124,000,000		$ 6,038,000,000
Long-term investments	90,000,000		131,000,000
Senior unsecured notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	5,500,000,000		5,500,000,000
Senior unsecured notes | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior unsecured notes	5,500,000,000		$ 5,500,000,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Upward adjustments to non-marketable equity securities	0	$ 0
Downward adjustments to non-marketable equity securities	42,000,000	$ 0
Cumulative upward adjustments to non-marketable equity securities	75,000,000
Cumulative downward adjustments to non-marketable equity securities	$ 55,000,000