Stock Based Compensation and Stock Options (Details 2) (USD $)	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Stock options
Options outstanding, beginning, Shares	1,100,952	1,502,046
Options granted, Shares	191,900	22,300
Options exercised, Shares	(64,976)	(131,146)
Options cancelled, Shares	(28,246)	(89,394)
Options outstanding, ending, Shares	1,199,630	1,303,806
Options outstanding, beginning, Average price per share	$ 18.65	$ 17.10
Options granted, Average Price	$ 23.46	$ 20.54
Options exercised, Average Price	$ 13.40	$ 12.73
Options Cancelled, Average Price	$ 23.36	$ 21.47
Options outstanding, ending, Average price per share	$ 19.60	$ 17.30