Indebtedness Indebtedness (Summary Of Principal Amount Of Liability Component, Unamoritized Disount And Net Carrying Amount Of Convertible Senior notes) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Non-current portion	$ 510,680	$ 496,037
Two Thousand Seven Notes [Member]
Debt Instrument [Line Items]
Principal amount	575,000	575,000
Unamortized debt discount	(64,320)	(78,963)
Net carrying amount	510,680	496,037
Total convertible senior notes, net	510,680	496,037
Less current portion	0	0
Non-current portion	$ 510,680	$ 496,037