CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flow from operating activities
Net income	$ 120,698	$ 52,606	$ 58,436
Adjustment to reconcile net income to cash provided by operating activities:
Depreciation and amortization	112,983	100,337	84,623
Impairment on real estate properties	272	26,344	155
Provisions for uncollectible mortgages, notes and accounts receivable		6,439
Amortization of deferred financing and refinancing costs	10,569	5,745	23,262
Restricted stock amortization expense	5,942	6,037	2,211
(Gain) loss on assets sold - net	(11,799)	(1,670)	4
Amortization of acquired in-place leases - net	(5,312)	(6,088)	(3,968)
Other	(663)	(150)	(93)
Gain on sale of securities			(789)
Change in operating assets and liabilities - net of amounts assumed/acquired:
Accounts receivable, net	(246)	(1,463)	(45)
Straight-line rent	(25,404)	(12,560)	(11,210)
Lease inducement	3,369	3,380	(6)
Effective yield receivable on mortgage notes	(2,235)	(1,341)
Other operating assets and liabilities	97	(7,601)	2,762
Operating assets and liabilities for owned and operated properties		(244)	2,221
Net cash provided by operating activities	208,271	169,771	157,563
Cash flow from investing activities
Acquisition of real estate - net of liabilities assumed and escrows acquired	(396,623)	(86,704)	(343,180)
Placement of mortgage loans	(11,969)	(130,042)	(20,657)
Proceeds from sale of real estate investments	29,023	5,150	81
Capital improvements and funding of other investments	(29,436)	(19,597)	(36,025)
Proceeds from other investments	15,355	6,983	21,324
Investments in other investments	(9,737)	(33,504)	(16,436)
Collection of mortgage principal - net	12,684	74	78
Net cash used in investing activities	(390,703)	(257,640)	(394,815)
Cash flow from financing activities
Proceeds from credit line borrowings	712,000	569,000	385,000
Payments of credit line borrowings	(726,500)	(296,500)	(479,100)
Receipts of other long-term borrowings	400,000		779,770
Payments of other long-term borrowings	(190,686)	(2,593)	(470,478)
Payments of financing related costs	(17,124)	(4,305)	(31,579)
Receipts from Dividend Reinvestment Plan - net	111,914	59,118	60,511
Payments for exercised options and restricted stock - net	(1,240)	(1,254)	(2,019)
Net proceeds from issuance of common stock	77,618	31,210	138,781
Dividends paid	(182,190)	(161,893)	(138,883)
Repurchase of common stock		(2,928)
Redemption of preferred stock		(108,556)
Net cash provided by financing activities	183,792	81,299	242,003
Increase (decrease) in cash and cash equivalents	1,360	(6,570)	4,751
Cash and cash equivalents at beginning of year	351	6,921	2,170
Cash and cash equivalents at end of year	1,711	351	6,921
Interest paid during the year, net of amounts capitalized	94,841	79,199	60,290
Non-cash investing activities:
Assumed debt obligations	80,946	101,259	202,015
Assumed other assets/liabilities	13,640
Non-cash settlement of mortgage obligations			(12,395)
Non-cash acquisition of real estate properties			12,395
Stock consideration issued for acquisition			19,693
Total non-cash real estate acquisition related items	$ 94,586	$ 101,259	$ 221,708