Earnings Per Share (Schedule Of Convertible Debt, By Dilutive and Anti-Dilutive Classification) (Detail) (Convertible Debt [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Mar. 31, 2012
New 4.0% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	$ 105,322	[1]	$ 105,322	[1]
New 4.25% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	97,000	[1]	97,000	[1]
Original 4.0% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	9,600	[2]	9,700	[2]
Original 4.25% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	3,000	[2]	3,000	[2]
Total Dilutive Convertible Debt [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	$ 215,000		$ 215,000

[1] Dilutive shares associated with the New Convertible Notes are attributable to the premium over the respective conversion prices.

[2] Dilutive shares associated with the Original Convertible Notes are attributable to the underlying principal amounts.