Fan Pier Leases (Details)	3 Months Ended	12 Months Ended
	Jun. 30, 2011 Y squarefeet leases	Dec. 31, 2012 squarefeet
Fan Pier Leases [Abstract]
Number of leases	2
Area of leased property (in square feet)	1,100,000	1,100,000
Number of buildings under lease agreement	2
Initial term of lease agreement (in years)	15
Optional term of lease agreement (in years)	10