Marketable Securities (Gross Unrealized Losses And Fair Values Of Investments By Investment Category And Length Of Time) (Details) (USD $)	Sep. 30, 2013	Mar. 31, 2013
Schedule of Investments [Line Items]
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Market Value	$ 27,943,551	$ 1,680,583
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	(362,235)	(13,342)
Marketable Securities, Continuous Unrealized Loss Position, Fair Market Value, Total	27,943,551	1,680,583
Marketable Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	(362,235)	(13,342)
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Market Value	26,514,541	1,171,976
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	(348,139)	(4,187)
Marketable Securities, Continuous Unrealized Loss Position, Fair Market Value, Total	26,514,541	1,171,976
Marketable Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	(348,139)	(4,187)
Municipal Bonds [Member]
Schedule of Investments [Line Items]
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Market Value	1,429,010	508,607
Marketable Securities, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	(14,096)	(9,155)
Marketable Securities, Continuous Unrealized Loss Position, Fair Market Value, Total	1,429,010	508,607
Marketable Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	$ (14,096)	$ (9,155)