Fair Value Disclosures (Activity for Interest Rate Swap Liabilities Classified as Level 3 Fair Value Measurements) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2010		Sep. 30, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 359,716,000		$ 300,040,000
Settlements	(35,609,000)		(271,283,000)
Less: total gains (losses) included in earnings	102,416,000	[1]	288,922,000	[1]
Less: total gains (losses) included in other comprehensive income (loss)	16,794,000		125,638,000
Ending Balance	443,317,000		443,317,000
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss) Included in Other Income	$ 93,800,000		$ 203,200,000

[1] Includes $93.8 million and $203.2 million, respectively, for the three and nine months ended September 30, 2010, of losses that are attributable to the change in unrealized gains or losses relating to liabilities still held at the reporting date.