Fair Value Disclosures (Estimated Fair Values and Carrying Amounts of Assets and Liabilities) (Details) (USD $)	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010	Dec. 31, 2009
Cash and cash equivalents, carrying value	$ 108,116,000		$ 112,531,000		$ 242,087,000	$ 766,146,000
Cash and cash equivalents, fair value	108,116,000		112,531,000
Restricted cash, current and non-current, carrying value	198,608,000		226,015,000
Restricted cash, current and non-current, fair value	198,608,000		226,015,000
Long-term debt and other obligations, carrying amount	6,816,258,000		6,778,894,000
Long-term debt and other obligations, fair value	7,222,647,000		7,121,156,000
Interest rate swaps, carrying amount	3,003,000	[1]	5,198,000	[1]
Interest rate swaps, fair value	3,003,000	[1]	5,198,000	[1]
Year 2007 Term Loans Interest Rate Swap Jan 2010 to Dec 2011 [Member]
Derivative notional amount	$ 600,000,000

[1] Variable to fixed interest rate swaps hedging a portion of the 2007 Term Loans until December 2011 with a notional value of $600.0 million