Additional Registrant Information (Details) $ in Millions	Aug. 01, 2024 shares	Jul. 31, 2024 USD ($) shares	Jul. 31, 2024 £ / shares	Feb. 29, 2024 £ / shares shares	Jul. 31, 2023 USD ($) shares	Jul. 31, 2023 £ / shares	Jul. 31, 2022 USD ($)
Additional Registrant Information [Line Items]
Cash and cash equivalents		$ 571			$ 601		$ 771
Total assets		16,572			15,994
Total liabilities		$ 10,956			$ 10,957
Ordinary shares, par value (in pound sterling per share) | £ / shares			£ 10			£ 10
Ordinary shares, shares authorized (in shares) | shares		500,000,000			500,000,000
Ordinary shares, shares issued (in shares) | shares		232,171,182			232,171,182
Ordinary shares, par value 10 pence: 500,000,000 shares authorized, 232,171,182 shares issued		$ 30			$ 30
Paid-in capital		864			809
Total liabilities and shareholders' equity		16,572			$ 15,994
Additional Registrant
Additional Registrant Information [Line Items]
Cash and cash equivalents		0
Total assets		0
Total liabilities		$ 0
Ordinary shares, par value (in pound sterling per share) | £ / shares			£ 0.0001	£ 0.03
Ordinary shares, shares authorized (in shares) | shares		500,000,000
Ordinary shares, shares issued (in shares) | shares	201,343,253	3		3
Ordinary shares, par value 10 pence: 500,000,000 shares authorized, 232,171,182 shares issued		$ 0
Paid-in capital		0
Total liabilities and shareholders' equity		$ 0
Ordinary shares, shares outstanding (in shares) | shares	201,343,253