Derivative and Other Fair Value Instruments (Details 3) (USD $) In Thousands	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009
Schedule of Location of Cash flow Hedges on Statement of Operations
Effective Portion - Amount of Gain/ (Loss) Recognized in OCI on Derivative	$ (65,894)	$ 37,676
Effective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	(3,338)	(3,724)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	0	0
Interest Expense [Member] \| Forward Starting Swaps/Treasury Locks [Member]
Schedule of Location of Cash flow Hedges on Statement of Operations
Effective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	(3,338)	(3,724)
Forward Starting Swaps/Treasury Locks [Member]
Schedule of Location of Cash flow Hedges on Statement of Operations
Effective Portion - Amount of Gain/ (Loss) Recognized in OCI on Derivative	(68,149)	34,432
Development Interest Rate Swaps/Caps [Member]
Schedule of Location of Cash flow Hedges on Statement of Operations
Effective Portion - Amount of Gain/ (Loss) Recognized in OCI on Derivative	$ 2,255	$ 3,244

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph b

+ Details

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- Definition

The effective portion of gains on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

+ Details

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- Definition

The income statement location of the effective portion of loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

+ Details

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