Common And Preferred Stock (Schedule Of Repurchases Of Shares) (Details) - Common Stock [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Stock Repurchased During Period, Shares	656,820	30,777	403,624
Cost of shares repurchased (in thousands of dollars)	$ 33,457	$ 1,443	$ 21,610
Weighted-average cost per share	$ 50.94	$ 46.87	$ 53.54