Share-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Shares
Outstanding, beginning of period (in shares)	871,200	994,900
Granted (in shares)	208,200	307,500
Exercised (in shares)	(336,900)	(363,400)
Forfeited or expired (in shares)	(2,100)	(47,500)
Outstanding, end of period (in shares)	740,400	891,500
Exercisable, end of period (in shares)	313,500	335,100
Weighted- Average Exercise Price
Outstanding, beginning of period, weighted-average exercise price (in USD per share)	$ 23.40	$ 15.24
Granted, weighted-average exercise price (in USD per share)	42.13	33.50
Exercised, weighted-average exercise price (in USD per share)	18.99	10.05
Forfeited or expired, weighted-average exercise price (in USD per share)	38.21	25.76
Outstanding, end of period, weighted-average exercise price (in USD per share)	30.63	23.09
Exercisable, end of period, weighted-average exercise price (in USD per share)	$ 21.68	$ 15.01
Options, Additional Disclosures:
Outstanding, end of period, weighted-average remaining contractual term	7 years 11 months	7 years 11 months
Exercisable, end of period, weighted-average remaining contractual term	6 years 8 months	6 years 8 months
Outstanding, end of period, aggregate intrinsic value	$ 15,325	$ 10,368
Exercisable, end of period, aggregate intrinsic value	$ 9,341	$ 6,604