Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Rental property revenues	$ 446,035	$ 249,814	$ 196,244
Fee income	8,632	8,347	7,297
Other	11,518	1,050	828
Total revenues	466,185	259,211	204,369
Expenses:
Rental property operating expenses	163,882	96,908	82,545
Reimbursed expenses	3,527	3,259	3,430
General and administrative expenses	27,523	25,592	16,918
Interest expense	33,524	26,650	22,735
Depreciation and amortization	196,745	97,948	71,625
Acquisition and transaction costs	1,661	24,521	299
Other	1,796	5,888	1,181
Total costs and expenses	428,658	280,766	198,733
(Gain) loss on extinguishment of debt	2,258	(5,180)	0
Income (loss) from continuing operations before unconsolidated joint ventures and gain (loss) on sale of investment properties	39,785	(26,735)	5,636
Income from unconsolidated joint ventures	47,115	10,562	8,302
Income (loss) from continuing operations before gain on sale of investment properties	86,900	(16,173)	13,938
Gain on sale of investment properties	133,059	77,114	80,394
Income from continuing operations	219,959	60,941	94,332
Income from discontinued operations:
Income from discontinued operations	0	19,163	31,848
Loss on sale from discontinued operations	0	0	(551)
Income from discontinued operations	0	19,163	31,297
Net income	219,959	80,104	125,629
Net income attributable to noncontrolling interests	(3,684)	(995)	(111)
Net income attributable to controlling interests	$ 216,275	$ 79,109	$ 125,518
Per common share information — basic:
Income from continuing operations for common stockholders (in usd per share)	$ 0.52	$ 0.24	$ 0.44
Income from discontinued operations for common stockholders (in usd per share)	0.00	0.07	0.14
Net income available to common stockholders (in usd per share)	0.52	0.31	0.58
Per common share information — diluted:
Income from continuing operations for common stockholders (in usd per share)	0.52	0.24	0.44
Income from discontinued operations for common stockholders (in usd per share)	0.00	0.07	0.14
Net income available to common stockholders (in usd per share)	$ 0.52	$ 0.31	$ 0.58
Weighted average shares — basic	415,610	253,895	215,827
Weighted average shares — diluted	423,297	256,023	215,979
Dividends declared per common share (in usd per share)	$ 0.30	$ 0.24	$ 0.32