Consolidated Statements Of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 78,090,000	$ 61,551,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	28,429,000	26,017,000
Amortization	1,772,000	1,709,000
Straight-line rental income	(10,583,000)	(12,308,000)
Non-cash interest income on construction loan	386,000	0
Non-cash write-off of straight-line rent receivable	14,726,000	0
Gain on sale of real estate	(4,582,000)	0
Gain on sale of marketable securities	(23,498,000)	0
Loan recovery	0	(491,000)
Share-based compensation	1,230,000	1,697,000
Amortization of commitment fees	(143,000)	0
Loss from equity-method investee	460,000	513,000
Change in operating assets and liabilities:
Equity-method investment and other assets	(109,000)	740,000
Accounts payable and accrued expenses	(431,000)	(1,004,000)
Deferred income	(1,780,000)	1,572,000
Net cash provided by operating activities	83,195,000	79,996,000
Cash flows from investing activities:
Investment in mortgage and other notes receivable	(41,673,000)	(52,580,000)
Collection of mortgage and other notes receivable	15,855,000	16,765,000
Investment in real estate	(261,610,000)	(3,261,000)
Investment in real estate development	(15,554,000)	(4,571,000)
Investment in renovations of existing real estate	(815,000)	(1,816,000)
Proceeds from disposition of real estate properties	27,723,000	0
Proceeds from sales of marketable securities	56,449,000	0
Net cash used in investing activities	(230,525,000)	(45,463,000)
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	157,000,000	(273,000,000)
Proceeds from issuance of secured debt	0	78,084,000
Borrowings on term loan	0	225,000,000
Payments on term loans	(381,000)	(368,000)
Debt issuance costs	0	(2,305,000)
Equity offerring costs	0	(275,000)
Value of shares withheld from options exercised for employee tax withholding	(822,000)	0
Proceeds from stock issuance	50,190,000	1,000
Distributions to noncontrolling interest	(866,000)	(869,000)
Dividends paid to stockholders	(67,201,000)	(60,795,000)
Net cash provided by (used in) financing activities	137,920,000	(34,527,000)
(Decrease) increase in cash and cash equivalents	(9,410,000)	6,000
Cash and cash equivalents, beginning of year	13,286,000	3,287,000
Cash and cash equivalents, end of year	3,876,000
Supplemental disclosure of cash flow information:
Interest Paid	19,057,000	13,723,000
Supplemental schedule of non-cash investing and financing activities:
Accounts payable related to investments in real estate	1,475,000	1,112,000
Reclass of note balance into real estate investment	0	255,000
Payment to terminate lease purchase option	(6,400,000)	0
Long-term escrow deposit	$ 4,500,000	$ 0