Consolidated Statements Of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
REVENUE
Rental Income	$ 932,738	$ 912,287	$ 854,286
Mortgage interest income	3,050	3,149	3,062
Total revenue	935,788	915,436	857,348
EXPENSES
Rental expenses	187,831	173,094	164,890
Real estate taxes	110,927	114,776	107,839
General and administrative	42,754	33,600	36,281
Depreciation and amortization	239,758	244,245	216,050
Total operating expenses	581,270	565,715	525,060
Gain on sale of real estate, net	116,393	11,915	77,922
OPERATING INCOME	470,911	361,636	410,210
Other interest income	1,266	942	475
Interest expense	(109,623)	(110,154)	(100,125)
Early extinguishment of debt	0	0	(12,273)
(Loss) income from real estate partnerships	(2,012)	(3,398)	(417)
Net income	360,542	249,026	297,870
Net income attributable to noncontrolling interests	(6,676)	(7,119)	(7,956)
NET INCOME ATTRIBUTABLE TO THE TRUST	353,866	241,907	289,914
Dividends on preferred shares	(8,042)	(8,042)	(2,458)
NET INCOME AVAILABLE FOR COMMON SHAREHOLDERS	$ 345,824	$ 233,865	$ 287,456
EARNINGS PER COMMON SHARE, BASIC
Net income available for common shareholders	$ 4.61	$ 3.18	$ 3.97
Weighted average common shares outstanding, basic	74,766	73,274	72,117
EARNINGS PER COMMON SHARE, DILUTED
Net income available for common shareholders	$ 4.61	$ 3.18	$ 3.97
Weighted average number of common shares	74,766	73,302	72,233
Comprehensive Income
Net income	$ 360,542	$ 249,026	$ 297,870
Other comprehensive (loss) income - change in value of interest rate swaps	(397)	(438)	2,599
COMPREHENSIVE INCOME	360,145	248,588	300,469
Comprehensive income attributable to noncontrolling interests	(6,676)	(7,119)	(7,956)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE TRUST	$ 353,469	$ 241,469	$ 292,513