JFK Redevelopment (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011
JFK Redevelopment [Line Items]
Construction in Progress, Gross	$ 234,000,000
Construction Payable	170,000,000
Term for completion of project	5
Estimated Cost Of Project	1,200,000,000
Special Project Bonds Face Amount	$ 800,000,000
Term of agreement to sublease space	33