Summary of Significant Accounting Policies (Interest Expense and Amortization of Deferred Financing Costs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of Significant Accounting Policies [Abstract]
Interest expense on debt obligations	$ 404,644	$ 404,815	$ 384,525
Amortization of deferred financing costs	15,086	15,397	26,953
Amortization of discounts on long-term debt	16,090	14,481	12,219
Amortization of interest rate swaps	71,707	54,169	18,818
Other, net of capitalized interest	60	1,407	3,367
Total	$ 507,587	$ 490,269	$ 445,882