v2.4.0.6
Fair Value Measurements (Schedule Of Carrying And Fair Values Of Long-Term Debt) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended 1 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2011
Jan. 31, 2006
6 5/8% Senior Notes Due 2016 [Member]
Dec. 31, 2011
6 5/8% Senior Notes Due 2016 [Member]
Dec. 31, 2010
6 5/8% Senior Notes Due 2016 [Member]
Jan. 13, 2006
6 5/8% Senior Notes Due 2016 [Member]
Dec. 31, 2011
GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Dec. 31, 2010
GO Zone 6 1/2% Senior Notes Due 2029 [Member]
Dec. 31, 2011
GO Zone 6 3/4% Senior Notes Due 2032 [Member]
Dec. 31, 2010
GO Zone 6 3/4% Senior Notes Due 2032 [Member]
Dec. 31, 2011
GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Dec. 31, 2010
GO Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Dec. 31, 2011
IKE Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Dec. 31, 2010
IKE Zone 6 1/2% Tax-Exempt Revenue Bonds Due 2035 [Member]
Dec. 31, 1997
Waste Disposal Revenue Bonds Due 2027 [Member]
Dec. 31, 2011
Waste Disposal Revenue Bonds Due 2027 [Member]
Dec. 31, 2010
Waste Disposal Revenue Bonds Due 2027 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]                                
Senior Notes, Carrying Value     $ 249,674 $ 249,593   $ 100,000 $ 100,000 $ 250,000 $ 250,000 $ 89,000 $ 89,000 $ 65,000 $ 65,000      
Senior Notes, Fair Value     254,890 258,438   108,834 99,875 263,988 251,925 93,090 88,653 67,987 64,905      
Loans, Carrying Value                             10,889 10,889
Loans, Fair Value                             $ 10,889 $ 10,889
Stated interest rate     6.625% 6.625% 6.625% 6.50% 6.50% 6.75% 6.75% 6.50% 6.50% 6.50% 6.50%      
Maturity date 2016 2016 2016     2029   2032   2035   2035   December 2027 2027