Debentures (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2023	Aug. 31, 2022	Sep. 01, 2020
Debt Instrument [Line Items]
Face amount of debt	$ 365		$ 365
Redemption period, end date			Nov. 13, 2023
Unpaid principal balance	365		$ 365
Fair Value, Option, Aggregate Differences, Long-term Debt Instruments	(18)		(18)
Interest expense, debt	2	$ 2	3	$ 3
Related Party Principal Amounts of 1.75% Debenture Owned	$ 330		$ 330
Fair Value Inputs, Entity Credit Risk	7.21%		7.21%		7.90%
Long-term debentures (note 5)					$ 456
Debenture implied discount					$ 91