Consolidated Statements Of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REVENUE
Rental income	$ 727,812	$ 666,322	$ 620,089
Other property income	11,810	14,758	12,169
Mortgage interest income	4,390	5,010	5,155
Total revenue	744,012	686,090	637,413
EXPENSES
Rental expenses	147,593	135,417	118,695
Real estate taxes	85,824	76,506	71,759
General and administrative	35,645	32,316	31,970
Depreciation and amortization	174,796	170,814	160,828
Total operating expenses	443,858	415,053	383,252
OPERATING INCOME	300,154	271,037	254,161
Other interest income	149	94	433
Interest expense	(92,553)	(93,941)	(104,977)
Early extinguishment of debt	(19,072)	(10,545)	(13,304)
Income from real estate partnerships	1,416	1,243	1,498
INCOME FROM CONTINUING OPERATIONS	190,094	167,888	137,811
DISCONTINUED OPERATIONS
Discontinued operations - income	0	0	942
Discontinued operations - gain on sale of real estate	0	0	23,861
Results from discontinued operations	0	0	24,803
Income before gain on sale of real estate	190,094	167,888	162,614
Gain on sale of real estate	28,330	4,401	4,994
Net income	218,424	172,289	167,608
Net income attributable to noncontrolling interests	(8,205)	(7,754)	(4,927)
NET INCOME ATTRIBUTABLE TO THE TRUST	210,219	164,535	162,681
Dividends on preferred shares	(541)	(541)	(541)
NET INCOME AVAILABLE FOR COMMON SHAREHOLDERS	$ 209,678	$ 163,994	$ 162,140
EARNINGS PER COMMON SHARE, BASIC
Continuing operations	$ 2.63	$ 2.35	$ 2.01
Discontinued operations	0.00	0.00	0.38
Gain on sale of real estate	0.41	0.07	0.08
EARNINGS PER COMMON SHARE, BASIC	$ 3.04	$ 2.42	$ 2.47
Weighted average common shares outstanding, basic	68,797	67,322	65,331
EARNINGS PER COMMON SHARE, DILUTED
Continuing operations	$ 2.62	$ 2.34	$ 2.00
Discontinued operations	0.00	0.00	0.38
Gain on sale of real estate	0.41	0.07	0.08
EARNINGS PER COMMON SHARE, DILUTED	$ 3.03	$ 2.41	$ 2.46
Weighted average number of common shares, diluted	68,981	67,492	65,483
Comprehensive Income
Net income	$ 218,424	$ 172,289	$ 167,608
Other comprehensive (loss) income - change in value of interest rate swaps	(595)	(2,098)	10,971
COMPREHENSIVE INCOME	217,829	170,191	178,579
Comprehensive income attributable to noncontrolling interests	(8,205)	(7,754)	(4,927)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE TRUST	$ 209,624	$ 162,437	$ 173,652