Stock Based Compensation and Stock Options - Stock Options (Detail) - $ / shares	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding, beginning balance	1,163,179	1,115,984
Options granted, Shares	39,700	37,550
Options exercised, Shares	(35,837)	(25,993)
Options cancelled, Shares		(9,011)
Options outstanding, ending balance	1,167,042	1,118,530
Options outstanding, beginning Average Price	$ 27.65	$ 24.80
Options granted, Average Price	34.67	44.86
Options exercised, Average Price	19.16	17.99
Options cancelled, Average Price		29.32
Option outstanding, Granted, Weighted Average Exercise per Share, ending balance	$ 28.15	$ 25.60