CONSOLIDATED STATEMENTS OF CASH FLOWS - Unaudited (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
OPERATING ACTIVITIES
Net Income	$ 20,502	$ 16,308
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization from continuing operations	46,817	42,552
Depreciation and amortization from discontinued operations	176	238
Stock-based compensation expense	2,781	1,910
Gain (Loss) on Sale of Property Plant Equipment	(2,036)	(27)
Changes in operating assets and liabilities:
Accrued income and other assets	2,832	1,007
Accounts payable, accrued expenses and prepaid rent	1,977	7,042
Other	134	(104)
NET CASH PROVIDED BY OPERATING ACTIVITIES	73,183	68,926
INVESTING ACTIVITIES
Real estate development	(34,834)	(28,982)
Purchases of real estate	(10,950)	(23,450)
Real estate improvements	(13,670)	(14,089)
Proceeds from sales of real estate investments	7,399	0
Changes in accrued development costs	72	2,313
Changes in other assets and other liabilities	(6,426)	(5,014)
NET CASH USED IN INVESTING ACTIVITIES	(58,409)	(69,222)
FINANCING ACTIVITIES
Proceeds from bank borrowings	186,072	213,034
Repayments on bank borrowings	(294,137)	(160,030)
Proceeds from mortgage notes payable	54,000	65,000
Principal payments on mortgage notes payable	(68,282)	(75,222)
Proceeds from Issuance of Long-term Debt	80,000	0
Debt issuance costs	(1,474)	(632)
Distributions paid to stockholders	(45,035)	(41,880)
Proceeds from common stock offerings	74,903	450
Proceeds from exercise of stock options	108	133
Proceeds from dividend reinvestment plan	168	184
Other	(244)	(431)
NET CASH USED IN FINANCING ACTIVITIES	(13,921)	606
DECREASE IN CASH AND CASH EQUIVALENTS	853	310
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	174	137
CASH AND CASH EQUIVALENTS AT END OF PERIOD	1,027	447
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest, net of amount capitalized of $3,362 and $2,695 for 2012 and 2011, respectively	$ 26,162	$ 25,340