CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income (Loss)	$ 41,428	$ (2,519)	$ (9,190)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities:
Depreciation	94,271	100,074	95,931
Amortization of Deferred Financing Costs	3,225	3,460	3,963
Other Amortization	30,632	35,097	36,390
Impairment of Real Estate	2,652	1,246	(2,661)
Provision for Bad Debt	726	542	1,110
Equity in Income of Joint Ventures	(136)	(1,559)	(980)
Distributions from Joint Ventures	177	1,580	1,033
Gain on Sale of Real Estate	(35,444)	(16,442)	(21,789)
Gain on Change in Control of Interests	0	(776)	(689)
Loss from Retirement of Debt	6,637	9,684	5,459
Mark-to-Market (Gain) Loss on Interest Rate Protection Agreements	(52)	328	1,718
(Increase) Decrease in Tenant Accounts Receivable, Prepaid Expenses and Other Assets, Net	(3,192)	3,770	(2,933)
Increase in Deferred Rent Receivable	(4,516)	(3,504)	(7,733)
(Decrease) Increase in Accounts Payable, Accrued Expenses, Other Liabilities, Rents Received in Advance and Security Deposits	(5,679)	10,791	(5,684)
Decrease in Restricted Cash	0	0	117
Payments of Premiums, Discounts and Prepayment Penalties Associated with Retirement of Debt	(4,978)	(7,065)	(6,528)
Cash Book Overdraft	0	1,715	0
Net Cash Provided by Operating Activities	125,751	136,422	87,534
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of Real Estate	(73,642)	(55,508)	(5,277)
Additions to Investment in Real Estate and Non-Acquisition Tenant Improvements and Lease Costs	(114,806)	(83,222)	(85,247)
Net Proceeds from Sales of Investments in Real Estate	126,250	82,503	75,953
Contributions to and Investments in Joint Ventures	(38)	(190)	(155)
Distributions from Joint Ventures	104	90	650
Repayments of Notes Receivable	615	14,365	10,394
Decrease (Increase) in Escrows	204	(273)	(97)
Net Cash Used in Investing Activities	(61,313)	(42,235)	(3,779)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt and Equity Issuance Costs	(3,575)	(1,545)	(7,162)
Proceeds from the Issuance of Common Stock, Net of Underwriter's Discount	174,081	134,905	202,845
Repurchase and Retirement of Restricted Stock	(2,968)	(2,690)	(1,001)
Common Stock and Unit Distributions	(29,025)	0	0
Preferred Dividends Paid	(8,733)	(23,258)	(15,254)
Redemption of Preferred Stock	(150,000)	(50,000)	0
Payments on Interest Rate Swap Agreement	(1,079)	(1,144)	(489)
Proceeds from Origination of Mortgage Loans Payable	0	100,599	255,900
Repayments on Mortgage and Other Loans Payable	(85,680)	(39,121)	(71,983)
Repayments of Senior Unsecured Notes	(29,769)	(166,153)	(234,307)
Proceeds from Unsecured Credit Facility	373,000	339,000	390,500
Repayments on Unsecured Credit Facility	(298,000)	(390,000)	(618,553)
Net Cash Used in Financing Activities	(61,748)	(99,407)	(99,504)
Net Effect of Exchange Rate Changes on Cash and Cash Equivalents	(51)	5	(61)
Net Increase (Decrease) in Cash and Cash Equivalents	2,690	(5,220)	(15,749)
Cash and Cash Equivalents, Beginning of Year	4,938	10,153	25,963
Cash and Cash Equivalents, End of Year	$ 7,577	$ 4,938	$ 10,153