Accounts Receivable, Net (Schedule of Accounts Receivable) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2011		Dec. 31, 2010
Straight-line rent receivable	$ 26,760		$ 27,003
Deferred rent receivable	4,420	[1]	4,420	[1]
Allowance for doubtful accounts	(6,554)		(6,691)
Total	34,983		39,814
Rent deferral payments bearing interest rate	8.70%
Tenants [Member]
Accounts receivable, gross	8,400		11,634
Non-Tenants [Member]
Accounts receivable, gross	122		155
Canada Revenue Agency [Member]
Accounts receivable, gross	1,835		3,293
Private Equity Firm Guarantor [Member]
Deferred rent receivable	3,400
Other Guarantor [Member]
Deferred rent receivable			$ 1,000

[1] Rent deferral payments of $3.4 million are guaranteed by a private equity firm. During the year ended December 31, 2010, the Company also granted an additional rent deferral of $1.0 million that is not guaranteed by the private equity firm. This amount has been fully reserved at June 30, 2011. Rent deferral payments are due on or before June 9, 2012 and bear interest at 8.7%.