Debentures - Change in Fair Value (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2023	Aug. 31, 2022	Feb. 28, 2023
Debt Instrument [Line Items]
Debenture total fair value adjustment	$ (6)	$ (10)	$ 16	$ (58)
Debentures (note 5)	$ 383		$ 383		$ 367