Stock Based Compensation and Stock Options (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Stock options
Options outstanding, beginning, Shares	632,265	799,034	751,023	813,970
Options outstanding, beginning, Weighted Average Exercise Per Share	$ 35.41	$ 30.62	$ 34.19	$ 29.26
Options granted, Shares	16,650	95,050	48,350	140,275
Options granted, Average Price	$ 43.22	$ 52.76	$ 43.12	$ 50.50
Options exercised, Shares	(28,938)	(54,366)	(130,617)	(109,339)
Options exercised, Average Price	$ 24.90	$ 27.57	$ 25.08	$ 25.36
Options cancelled, Shares	(24,183)	(159)	(72,962)	(5,347)
Options cancelled, Average Price	$ 44.58	$ 29.41	$ 43.58	$ 28.41
Options outstanding, ending, Shares	595,794	839,559	595,794	839,559
Options outstanding, ending, Weighted Average Exercise Per Share	$ 35.76	$ 33.32	$ 35.76	$ 33.32