Stock-Based Compensation (Schedule Of Market-Based Restricted Stock Unit Activity) (Details) (Market-Based Restricted Stock Units [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Market-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]
Beginning balance	925
Granted	555
Vested	(304)
Forfeited or cancelled	(114)
Ending balance	1,062
Weighted-average grant date fair value, beginning balance	$ 19.16
Weighted-average grant date fair values of market-based restricted stock rights granted	$ 29.52	$ 10.45
Weighted-average grant date fair value, vested during period	$ 16.01
Weighted-average grant date fair value, forfeited or cancelled during period	$ 24.93
Weighted-average grant date fair value, ending balance	$ 24.86