Carrying Amounts and Fair Values of Financial Instruments for Which the Fair Value Option Was Not Elected (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Option, Disclosures Related to Election, Items Existing at Effective Date [Line Items]
Cash and Cash Equivalents	$ 25,058,000	$ 21,878,000	$ 287,313,000	$ 375,736,000
Notes and Loans Payable, Current	0	(25,073,000)
Secured Debt, Current	(30,119,000)	(37,846,000)
Long-term debt	(3,128,804,000)	(3,129,017,000)
Carrying Amount
Fair Value, Option, Disclosures Related to Election, Items Existing at Effective Date [Line Items]
Cash and Cash Equivalents	25,058,000	21,878,000
Restricted cash	20,383,000	68,673,000
Long-term debt	(3,128,804,000)	(3,129,017,000)
Fair Value
Fair Value, Option, Disclosures Related to Election, Items Existing at Effective Date [Line Items]
Cash and Cash Equivalents	25,058,000	21,878,000
Restricted cash	20,383,000	68,673,000
Long-term debt	$ (3,396,271,000)	$ (3,378,058,000)