CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Rental and other income	$ 1,674,011	$ 1,451,419	$ 990,370
Management, development and other fees	11,050	11,502	10,257
Total revenue	1,685,061	1,462,921	1,000,627
Expenses:
Operating expenses, excluding property taxes	410,672	352,245	259,350
Property taxes	178,634	158,774	97,555
Interest expense, net	180,618	172,402	136,920
Loss on extinguishment of debt, net	412	14,921	1,179
Loss on interest rate contract	0	51,000	0
Depreciation expense	442,682	560,215	243,680
General and administrative expense	41,425	39,573	34,101
Expensed acquisition, development and other pursuit costs, net of recoveries	(3,717)	45,050	11,350
Casualty and impairment loss	0	0	1,449
Total expenses	1,250,726	1,394,180	785,584
Equity in income (loss) of unconsolidated entities	148,766	(11,154)	20,914
Gain on sale of land	490	240	280
Gain on sale of communities	84,925	0	0
Gain on acquisition of unconsolidated entity	0	0	14,194
Income from continuing operations before taxes	668,516	57,827	250,431
Income tax expense	9,368	0	0
Income from continuing operations	659,148	57,827	250,431
Discontinued operations:
Income from discontinued operations	310	16,713	26,820
Gain on sale of real estate assets	37,869	278,231	146,311
Total discontinued operations	38,179	294,944	173,131
Net income	697,327	352,771	423,562
Net (income) loss attributable to noncontrolling interests	(13,760)	370	307
Net income attributable to common stockholders	683,567	353,141	423,869
Other comprehensive income:
Unrealized loss on cash flow hedges	(121)	0	(22,876)
Cash flow hedge losses reclassified to earnings	6,237	59,376	1,889
Comprehensive income	$ 689,683	$ 412,517	$ 402,882
Earnings per common share—basic:
Income (loss) from continuing operations attributable to common stockholders (in dollars per share)	$ 4.93	$ 0.46	$ 2.57
Discontinued operations attributable to common stockholders (in dollars per share)	$ 0.29	$ 2.32	$ 1.77
Net income attributable to common stockholders (in dollars per share)	$ 5.22	$ 2.78	$ 4.34
Earnings per common share—diluted:
Income (loss) from continuing operations attributable to common stockholders (in dollars per share)	$ 4.92	$ 0.46	$ 2.55
Discontinued operations attributable to common stockholders (in dollars per share)	$ 0.29	$ 2.32	$ 1.77
Net income attributable to common stockholders (in dollars per share)	$ 5.21	$ 2.78	$ 4.32