Stock-Based Compensation and Stock Options - Stock Options (Detail) - $ / shares	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options outstanding, beginning balance	1,143,928	1,115,465
Options granted, Shares	77,400	44,900
Options exercised, Shares	(65,921)	(76,623)
Options cancelled/forfeited, Shares	(3,685)	(9,221)
Options outstanding, ending balance	1,151,722	1,074,521
Options outstanding, beginning balance, Weighted Average Exercise Price	$ 32.02	$ 30.36
Options granted, Weighted Average Exercise Price	45.93	45.74
Options exercised, Weighted Average Exercise Price	26.67	22.11
Options cancelled/forfeited, Weighted Average Exercise Price	39.99	35.43
Options outstanding, ending balance, Weighted Average Exercise Price	$ 33.24	$ 31.56