Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Cash flows from operating activities
Net income	$ 105,378		$ 37,559		$ 40,948
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of real estate	(97,491)		(21,599)		(13,348)
Depreciation and amortization, including amounts in discontinued operations	100,528		95,746		94,447
Provision for losses on accounts receivable	4,005		4,150		6,889
Real estate impairment, including amounts in discontinued operations	15,125		0		0
Amortization of share grants, net	4,321		4,931		3,085
Amortization of debt premiums, discounts and related financing costs	3,194		5,532		6,957
Loss (gain) on extinguishment of debt, net	0		9,176		(5,336)
Changes in operating other assets	(14,911)		(20,053)		(14,576)
Changes in operating other liabilities	(2,294)		(3,509)		(16,165)
Net cash provided by operating activities	117,855		111,933		102,901
Cash flows from investing activities
Real estate acquisitions, net	(281,701)	[1]	(155,881)	[1]	(19,828)	[1]
Capital improvements to real estate	(32,815)		(25,045)		(27,337)
Held for development	(25,929)		(1,337)		(2,135)
Net cash received for sale of real estate	402,164		71,505		36,842
Non-real estate capital improvements	(621)		(392)		(351)
Net cash provided by (used in) investing activities	61,098		(111,150)		(12,809)
Cash flows from financing activities
Line of credit borrowings	261,000		68,800		214,500
Line of credit repayments	(262,000)		(96,800)		(153,500)
Dividends paid	(115,045)		(108,949)		(100,221)
Distributions to noncontrolling interests	(2,488)		(163)		(190)
Proceeds from equity offerings under dividend reinvestment program	5,043		5,286		2,479
Proceeds from mortgage notes payable	0		0		37,500
Principal payments - mortgage notes payable	(32,331)		(25,985)		(54,030)
Net proceeds from debt offerings	0		247,998		0
Financing costs	(3,905)		(2,450)		(847)
Net proceeds from equity offerings	0		168,880		160,915
Notes payable repayments, including penalties for early extinguishment	(96,521)		(193,799)		(197,414)
Net proceeds from exercise of share options	1,292		3,963		45
Net cash provided by and (used in) financing activities	(244,955)		66,781		(90,763)
Net increase (decrease) in cash and cash equivalents	(66,002)		67,564		(671)
Cash and cash equivalents at beginning of year	78,767		11,203		11,874
Cash and cash equivalents at end of period	12,765		78,767		11,203
Supplemental disclosure of cash flow information:
Cash paid for interest, net of amounts capitalized	$ 63,916		$ 60,622		$ 69,292

[1] See note 3 to the consolidated financial statements for the supplemental disclosure of non-cash investing and financing activities, including the assumption of mortgage debt in conjunction with some of our real estate acquisitions.