Consolidated Statements of Income (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Rental income	$ 1,405,767,000		$ 1,227,589,000		$ 1,063,214,000
Resident fees and services	1,892,237,000		1,616,290,000		697,494,000
Interest income	37,667,000		32,663,000		39,065,000
Other income	7,875,000		4,066,000		5,271,000
Total revenues	3,343,546,000		2,880,608,000		1,805,044,000
Expenses:
Interest expense	481,039,000		458,360,000		361,565,000
Property operating expenses	1,403,358,000		1,206,813,000		567,989,000
Depreciation and amortization	844,130,000		865,800,000		506,220,000
General and administrative	142,943,000		108,318,000		97,341,000
Transaction costs	69,538,000		133,401,000		61,609,000
Loss (gain) on derivatives, net	1,495,000		(4,470,000)		1,825,000
Loss (gain) on extinguishment of debt, net	9,558,000		(909,000)		(775,000)
Provision for loan losses	0		2,110,000		27,008,000
Other expenses	10,262,000		0		0
Total expenses	2,959,333,000		2,778,363,000		1,619,132,000
Income from continuing operations before income taxes and income from unconsolidated entities	384,213,000		102,245,000		185,912,000
Income tax (expense) benefit	1,267,000		(7,491,000)		(7,612,000)
(Loss) income from unconsolidated entities	(27,426,000)		(8,187,000)		2,482,000
Income from continuing operations	358,054,000		86,567,000		180,782,000
Discontinued operations:
Gain (loss) on sales of properties, net	6,411,000		49,138,000		100,549,000
Impairment of assets	0		0		(29,287,000)
Income (loss) from discontinued operations	724,000		2,575,000		42,796,000
Discontinued operations, net	7,135,000		51,713,000		114,058,000
Gain (loss) on real estate dispositions, net	147,111,000		0		0
Net income	512,300,000		138,280,000		294,840,000
Less: Preferred stock dividends	65,408,000		66,336,000		69,129,000
Less: Preferred stock redemption charge	0		0		6,242,000
Net Income Loss Attributable To Noncontrolling Interest	147,000	[1]	(6,770,000)	[1]	(2,415,000)	[1]
Net income attributable to common stockholders	$ 446,745,000		$ 78,714,000		$ 221,884,000
Average number of common shares outstanding:
Basic	306,272,000		276,929,000		224,343,000
Diluted	307,747,000		278,761,000		225,953,000
Basic:
Income from continuing operations attributable to common stockholders	$ 1.44		$ 0.1		$ 0.48
Discontinued operations, net	$ 0.02		$ 0.19		$ 0.51
Basic earnings per share	$ 1.46		$ 0.28		$ 0.99
Diluted:
Income from continuing operations attributable to common stockholders	$ 1.43		$ 0.1		$ 0.48
Discontinued operations, net	$ 0.02		$ 0.19		$ 0.5
Diluted earnings per share	$ 1.45		$ 0.28		$ 0.98

[1] * Amounts may not sum due to rounding (1) Includes amounts attributable to redeemable noncontrolling interests