Stock-Based Compensation (Summary Of Stock Options And Warrants) (Details) (USD $)	12 Months Ended
	Mar. 31, 2013 Option Shares Reserved [Member]	Mar. 31, 2012 Option Shares Reserved [Member]	Mar. 31, 2011 Option Shares Reserved [Member]	Mar. 31, 2013 Options [Member]	Mar. 31, 2012 Options [Member]	Mar. 31, 2011 Options [Member]	Mar. 31, 2013 Warrants [Member]	Mar. 31, 2011 Warrants [Member]	Mar. 31, 2010 Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Beginning	162,230	166,230	170,230	109,000	175,000	254,500	10,000	10,000	10,000
Granted	(4,000)	(4,000)	(4,000)	4,000	4,000	4,000
Exercised				(64,000)	(70,000)	(83,500)
Terminated							(6,000)
Options Outstanding, Ending	158,230	162,230	166,230	49,000	109,000	175,000	4,000	10,000	10,000
Weighted Average Option Exercise Price, Beginning				$ 25.85	$ 21.54	$ 17.28	$ 16.28	$ 16.28	$ 16.28
Granted				$ 54.11	$ 58.25	$ 42.45
Exercised				$ 24.23	$ 16.93	$ 9.56
Terminated							$ 7.35
Weighted Average Option Exercise Price, Ending				$ 30.27	$ 25.85	$ 21.54	$ 29.69	$ 16.28	$ 16.28