Earnings Per Share (Schedule Of Convertible Debt, By Dilutive and Anti-Dilutive Classification) (Detail) (Convertible Debt [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012	Jun. 30, 2012
New 4.0% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	$ 105,322	[1]	$ 105,300	$ 105,322	[1]
New 4.25% Notes [Member]
Dilutive Securities [Abstract]
Convertible debt, outstanding principal amount	97,000	[1]	97,000	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 weighted average premium value, in shares, of the conversion shares underlying the New Convertible Notes in excess of the respective principal amounts thereof.

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