Share-Based Compensation (Options Granted Under Stock Option Plans) (Details) shares in Thousands	6 Months Ended
	Jul. 31, 2021 $ / shares shares
Number of Shares
Options outstanding at beginning of year	3,540
Granted	183
Exercised	(302)
Expired or cancelled	(122)
Options outstanding at end of period	3,299
Options exercisable at end of period	2,497
Options available for future grant at end of period	5,491
Weighted-Average Exercise Price
Options outstanding at beginning of year | $ / shares	$ 47.17
Granted | $ / shares	53.82
Exercised | $ / shares	33.31
Expired or cancelled | $ / shares	52.43
Options outstanding at end of period | $ / shares	48.61
Options exercisable at end of period | $ / shares	$ 53.74
Options outstanding, weighted-average remaining contractual life	5 years 6 months
Options exercisable at end of period, Weighted-average remaining contractual life	4 years 4 months 24 days