Capital Stock - Changes in Issued and Outstanding Common Shares (Details) - USD ($) $ in Millions	3 Months Ended
	May 31, 2020	May 31, 2019
Common Stock [Roll Forward]
Capital stock outstanding, Shares, Beginning Balance	554,199,016
Capital stock outstanding, Shares, Ending Balance	555,622,606
Common Stock, Amount [Roll Forward]
Exercise of stock options	$ 1	$ 1
Stock-based compensation	13	17
Employee share purchase plan	$ 3	2
Capital Stock and Additional Paid-in Capital
Common Stock [Roll Forward]
Capital stock outstanding, Shares, Beginning Balance	554,199,000
Exercise of stock options	300,000
Common shares issued for restricted share unit settlements	325,000
Common shares issued for employee share purchase plan	799,000
Capital stock outstanding, Shares, Ending Balance	555,623,000
Common Stock, Amount [Roll Forward]
Common Stock, Value, Outstanding	$ 2,760
Exercise of stock options	1	1
Stock-based compensation	13	17
Employee share purchase plan	3	$ 2
Common Stock, Value, Outstanding	$ 2,777