Earnings Per Share and Stock Plans (Summary of Option Transactions) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised	(27,848)	(16,033)	(87,210)
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding, at Beginning of the year	718,801	612,149	612,506
Granted	398,945	157,999	118,060
Exercised	(27,848)	(16,033)	(87,210)
Cancelled	(26,004)	(35,314)	(31,207)
Number of options, Outstanding, Closing Balance	1,063,894	718,801	612,149
Exercisable at end of period	481,883
Beginning of year, Average Option Price	$ 20.13	$ 18.86	$ 17.05
Granted	17.00	24.94	27.08
Exercised	15.76	15.07	18.41
Cancelled	19.06	21.90	15.71
End of year, Average Option Price	19.10	$ 20.13	$ 18.86
End of year, Average Exercisable Price	$ 18.48
Outstanding at period end, Weighted average Remaining Contractual Life (in years)	6 years 11 months 23 days	6 years 7 months 21 days
Exercisable at period end, Weighted average Remaining Contractual Life (in years)	4 years 10 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 6,477	$ 465
Exercisable at end of period, Aggregate Intrinsic Value	$ 3,233