Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Supplemental Cash Flow Information
Interest paid, net of amounts capitalized	$ 61,300	$ 108,537
Income taxes paid	1,065	2,026
Non-cash investing activities:
Property and equipment additions in accounts payable and accrued liabilities	18,055	14,042
Transfer of real estate and lease intangibles through cancellation of debt	24,571	21,346
Transfer of investment through cancellation of debt	4,259
Non-cash financing activities:
Common stock issued in distribution reinvestment plan	9,820	9,983
Mortgage notes assumed by the Company		2,092
Accrual for distributions declared	2,493	2,477
Mortgage notes assumed by purchaser	73,119	28,754
Cancellation of debt through transfer of real estate	30,814	22,260
Issuance of Series A Convertible Preferred Stock	$ 2,700