Stock-Based Compensation (ESPP - Purchase Option Activity) (Details) (Employee Stock Purchase Plan, Purchase Option [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Dec. 31, 2011
Employee Stock Purchase Plan, Purchase Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at the beginning of period, Number of Stock Options	67
Granted, Number of Stock Options	291
Exercised, Number of Stock Options	(210)
Outstanding at the end of period, Number of Stock Options	148
Outstanding at the beginning of period, Weighted-Average Exercise Price	$ 51.03
Granted, Weighted-Average Exercise Price	$ 53.97
Exercised, Weighted-Average Exercise Price	$ 54.20
Outstanding at the end of period, Weighted-Average Exercise Price	$ 52.31