Capital Stock - Changes in Issued and Outstanding Common Shares (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2021	Aug. 31, 2020
Common Stock [Roll Forward]
Capital stock outstanding, Shares, Beginning Balance			565,505,328
Capital stock outstanding, Shares, Ending Balance	566,994,978		566,994,978
Common Stock, Amount [Roll Forward]
Exercise of stock options	$ 1	$ 2	$ 2	$ 3
Stock-based compensation	$ 10	9	17	22
Employee share purchase plan			$ 3	3
Capital Stock and Additional Paid-in Capital
Common Stock [Roll Forward]
Capital stock outstanding, Shares, Beginning Balance			565,505,000
Exercise of stock options			379,000
Common shares issued for restricted share unit settlements			732,000
Common shares issued for employee share purchase plan			379,000
Capital stock outstanding, Shares, Ending Balance	566,995,000		566,995,000
Common Stock, Amount [Roll Forward]
Common Stock, Value, Outstanding			$ 2,823
Exercise of stock options	$ 1	2	2	3
Stock-based compensation	10	$ 9	17	22
Employee share purchase plan			3	$ 3
Common Stock, Value, Outstanding	$ 2,845		$ 2,845