Earnings Per Share (Excluded Securities On Diluted Shares Calculation) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Convertible Senior Notes 2025 [Member]	Mar. 31, 2012 Convertible Senior Notes 2032 [Member]	Mar. 31, 2012 Convertible Senior Notes 2032 [Member]	Mar. 31, 2011 Convertible Senior Notes 2025 [Member]	Mar. 31, 2010 Convertible Senior Notes 2025 [Member]
Diluted	104,989	104,903
Debt Instrument, Convertible, Conversion Price					$ 25.02	$ 32.14	$ 32.14
Debt Instrument, Convertible, Stock Price Trigger			$ 38.57	$ 32.53