Stock-Based Compensation And Employee Benefit Plans (Schedule Of Performance-Based Restricted Stock Unit Activity) (Details) (Performance Based Restricted Stock Units [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2013
Performance Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Balance as of March 31, 2012	1,421
Vested	19
Forfeited or cancelled	(78)
Balance as of March 31, 2013	1,324
Weighted-Average Grant Date Fair Values, Balance as of March 31, 2012	$ 50.35
Weighted-Average Grant Date Fair Values, Vested	$ 15.39
Weighted-Average Grant Date Fair Values, Forfeited or cancelled	$ 38.67
Weighted-Average Grant Date Fair Values, Balance as of March 31, 2013	$ 51.54