Debt (Schedule Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Debt service guaranty liability	$ 74,075		$ 74,075
Unsecured notes payable under revolving credit facilities	170,000		166,500
Obligations under capital leases	21,000		21,000
Total	2,497,561	[1]	2,531,837	[1]
Debt Payable To 2038 [Member]
Debt Instrument [Line Items]
Debt payable to 2038 at 1.5% to 8.8%	2,230,979		2,268,668
Debt maturity date	2038
Industrial Revenue Bonds Payable To 2015 [Member]
Debt Instrument [Line Items]
Industrial revenue bonds payable to 2015 at 2.4%	$ 1,507		$ 1,594
Debt maturity date	2015
Debt instrument stated interest percentage	2.40%
Maximum [Member] | Debt Payable To 2038 [Member]
Debt Instrument [Line Items]
Debt instrument stated interest percentage	8.80%
Minimum [Member] | Debt Payable To 2038 [Member]
Debt Instrument [Line Items]
Debt instrument stated interest percentage	1.50%

[1] Consolidated Variable Interest Entities' Assets and Liabilities included in the above balances (See Note 17):