Dividends and Treasury Stock (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Jan. 31, 2015
Stockholders' Equity Note [Abstract]
Stock Repurchase Program, Authorized Amount	$ 75,000		$ 75,000		$ 40,000
Shares repurchased, Treasury Stock	0	169,474	0	332,651
Payments for Repurchase of Common Stock		$ 5,000	$ 0	$ 10,781
Unpaid repurchases of common stock	$ 0	$ 0	0	$ 0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 17,179		$ 17,179