Debt And Other Financing Arrangements (Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Long-term Debt, Total	$ 718,886	$ 719,615
Less current maturities	(550)	(1,400)
Long-term debt	718,336	718,215
Promissory Note, 2.61%, Due 2012 [Member]
Debt Instrument [Line Items]
Senior Notes	550	1,400
Rate of interest on Notes	2.61%
Maturity date	2012
7.25% Senior Notes Due 2018 [Member]
Debt Instrument [Line Items]
Senior Notes	425,000	425,000
Rate of interest on Notes	7.25%
Maturity date	2018
6.70% Senior Debentures Due 2034 [Member]
Debt Instrument [Line Items]
Senior Notes	300,000	300,000
Discount	(6,664)	(6,785)
Senior notes after fair market value adjustment and discount	$ 293,336	$ 293,215
Rate of interest on Notes	6.70%
Maturity date	2034