Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating revenues:
Total property revenues	$ 243,390	$ 127,743
Total operating revenues	243,487	127,920
Property operating expenses:
Depreciation and amortization	90,013	32,195
Acquisition (credit) expenses	11	10
Property management expenses	7,011	5,108
General and administrative expenses	4,342	3,239
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	9,819	20,223
Discontinued operations:
Net Income (Loss) Attributable to Noncontrolling Interest	848	825
Earnings per share - diluted:
Dividends declared per common share		$ 0.695
Distribution Made to Limited Partner, Distributions Declared, Per Unit	$ 0.7300	$ 0.6950
Parent Company [Member]
Operating revenues:
Rental revenues	220,988	117,705
Other property revenues	22,402	10,038
Total property revenues	243,390	127,743
Management fee income	97	177
Total operating revenues	243,487	127,920
Property operating expenses:
Personnel	24,909	13,981
Building repairs and maintenance	6,399	3,129
Real estate taxes and insurance	31,131	15,488
Utilities	13,478	6,565
Landscaping	5,408	2,866
Other operating	16,038	8,492
Depreciation and amortization	90,013	32,195
Total property operating expenses	187,376	82,716
Acquisition (credit) expenses	11	10
Property management expenses	7,011	5,108
General and administrative expenses	4,342	3,239
Merger related expenses	2,076	0
Integration related expenses	3,842	0
Income from continuing operations before non-operating items	38,829	36,847
Interest and other non-property income	160	47
Interest expense	(30,676)	(15,545)
Loss on debt extinguishment/modification	0	(169)
Amortization of deferred financing costs	(1,311)	(804)
Net casualty loss and other settlement proceeds	(10)	16
Income from continuing operations before income tax expense	6,992	20,392
Income Tax Expense	(270)	(223)
Income (Loss) from Continuing Operations before Equity Method Investments	6,722	20,169
Loss from real estate joint ventures	(24)	54
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	6,698	20,223
Discontinued operations:
(Loss) income from discontinued operations before gain on sale	416	1,782
Net casualty loss on insurance and other settlement proceeds on discontinued operations	(2)	0
Gain on sale of discontinued operations	5,481	0
Income (Loss) before Gain or Loss on Sale of Properties, and Extraordinary Items	12,593	22,005
Gain (Loss) on Disposition of Property Plant Equipment	2,564	0
Gain (Loss) on Disposition of Other Assets	557	0
Consolidated net income	15,714	22,005
Net Income (Loss) Attributable to Noncontrolling Interest	848	825
Net Income (Loss) Available to Common Stockholders, Basic	14,866	21,180
Earnings per common share - basic:
Income from continuing operations available for common shareholders	$ 0.12	$ 0.46
Discontinued property operations	$ 0.08	$ 0.04
Net income available for common shareholders	$ 0.20	$ 0.50
Earnings per share - diluted:
Income from continuing operations available for common shareholders	$ 0.12	$ 0.46
Discontinued property operations	$ 0.08	$ 0.04
Net income available for common shareholders	$ 0.20	$ 0.50
Dividends declared per common share	$ 0.73	$ 0.6950
Limited Partner [Member]
Operating revenues:
Rental revenues	220,988	117,705
Other property revenues	22,402	10,038
Total property revenues	243,390	127,743
Management fee income	97	177
Total operating revenues	243,487	127,920
Property operating expenses:
Personnel	24,909	13,981
Building repairs and maintenance	6,399	3,129
Real estate taxes and insurance	31,131	15,488
Utilities	13,478	6,565
Landscaping	5,408	2,866
Other operating	16,038	8,492
Depreciation and amortization	90,013	32,195
Total property operating expenses	187,376	82,716
Acquisition (credit) expenses	11	10
Property management expenses	7,011	5,108
General and administrative expenses	4,342	3,239
Merger related expenses	2,076	0
Integration related expenses	3,842	0
Income from continuing operations before non-operating items	38,829	36,847
Interest and other non-property income	160	47
Interest expense	(30,676)	(15,545)
Loss on debt extinguishment/modification	0	(169)
Amortization of deferred financing costs	(1,311)	(804)
Net casualty loss and other settlement proceeds	(10)	16
Income from continuing operations before income tax expense	6,992	20,392
Income Tax Expense	(270)	(223)
Income (Loss) from Continuing Operations before Equity Method Investments	6,722	20,169
Loss from real estate joint ventures	(24)	54
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	6,698	20,223
Discontinued operations:
(Loss) income from discontinued operations before gain on sale	416	1,570
Net casualty loss on insurance and other settlement proceeds on discontinued operations	(2)	0
Gain on sale of discontinued operations	5,481	0
Income (Loss) before Gain or Loss on Sale of Properties, and Extraordinary Items	12,593	21,793
Gain (Loss) on Disposition of Property Plant Equipment	2,564	0
Gain (Loss) on Disposition of Other Assets	557	0
Consolidated net income	15,714	21,793
Net Income (Loss) Available to Common Stockholders, Basic	$ 15,714	$ 21,793
Earnings per common share - basic:
Income from continuing operations available for common shareholders	$ 0.12	$ 0.46
Discontinued property operations	$ 0.08	$ 0.03
Net income available for common shareholders	$ 0.20	$ 0.49
Earnings per share - diluted:
Income from continuing operations available for common shareholders	$ 0.12	$ 0.46
Discontinued property operations	$ 0.08	$ 0.03
Net income available for common shareholders	$ 0.20	$ 0.49
Distribution Made to Limited Partner, Distributions Declared, Per Unit	$ 0.7300	$ 0.6950