Share-Based Compensation (Options Granted Under Stock Option Plans) (Details) shares in Thousands	3 Months Ended
	Apr. 30, 2022 $ / shares shares
Number of Shares
Options outstanding at beginning of year	3,211
Granted	506
Exercised	(74)
Expired or cancelled	(115)
Options outstanding at end of period	3,528
Options exercisable at end of period	2,665
Options available for future grant at end of period	2,296
Weighted-Average Exercise Price
Options outstanding at beginning of year | $ / shares	$ 48.84
Granted | $ / shares	30.97
Exercised | $ / shares	28.75
Expired or cancelled | $ / shares	54.60
Options outstanding at end of period | $ / shares	46.51
Options exercisable at end of period | $ / shares	$ 51.41
Options outstanding, weighted-average remaining contractual life	5 years 6 months
Options exercisable at end of period, Weighted-average remaining contractual life	4 years 3 months 18 days