Share-Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Shares
Outstanding, beginning of period (in shares)	871,200	994,900
Granted (in shares)	186,300	307,500
Exercised (in shares)	(330,400)	(93,800)
Forfeited or expired (in shares)	(900)	(31,600)
Outstanding, end of period (in shares)	726,200	1,177,000
Exercisable, end of period (in shares)	322,500	375,100
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)	41.44	33.50
Exercised, weighted-average exercise price (in USD per share)	19.15	13.80
Forfeited or expired, weighted-average exercise price (in USD per share)	33.50	25.49
Outstanding, end of period, weighted-average exercise price (in USD per share)	29.95	19.85
Exercisable, end of period, weighted-average exercise price (in USD per share)	$ 21.54	$ 15.23
Options, Additional Disclosures:
Outstanding, end of period, weighted-average remaining contractual term	8 years 3 months 18 days	7 years 9 months 18 days
Exercisable, end of period, weighted-average remaining contractual term	7 years 2 months 12 days	7 years 3 months 18 days
Outstanding, end of period, aggregate intrinsic value	$ 11,830	$ 16,527
Exercisable, end of period, aggregate intrinsic value	$ 7,966	$ 6,998