Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Rental property revenues	$ 249,814	$ 196,244	$ 164,123
Fee income	8,347	7,297	12,519
Other	1,050	828	919
Total revenues	259,211	204,369	177,561
Costs and expenses:
Rental property operating expenses	96,908	82,545	76,963
Reimbursed expenses	3,259	3,430	3,652
General and administrative expenses	25,592	16,918	19,784
Interest expense	26,650	22,735	20,983
Depreciation and amortization	97,948	71,625	62,258
Acquisition and merger costs	24,521	299	1,130
Other	5,888	1,181	3,729
Total costs and expenses	280,766	198,733	188,499
Loss on extinguishment of debt	(5,180)	0	0
Income (loss) from continuing operations before benefit for income taxes, income from unconsolidated joint ventures, and gain on sale of investment properties	(26,735)	5,636	(10,938)
Benefit for income taxes from operations	0	0	20
Income from unconsolidated joint ventures	10,562	8,302	11,268
Income (loss) from continuing operations before gain on sale of investment properties	(16,173)	13,938	350
Gain on sale of investment properties	77,114	80,394	12,536
Income from continuing operations	60,941	94,332	12,886
Income (loss) from discontinued operations:
Income from discontinued operations	19,163	31,848	20,764
Income (loss) on sale from discontinued operations	0	(551)	19,358
Income from discontinued operations	19,163	31,297	40,122
Net income	80,104	125,629	53,008
Net income attributable to noncontrolling interests	(995)	(111)	(1,004)
Income from discontinued operations	79,109	125,518	52,004
Preferred share original issuance costs	0	0	(3,530)
Net income attributable to noncontrolling interests	0	0	(2,955)
Net income attributable to controlling interests	$ 79,109	$ 125,518	$ 45,519
Per common share information — basic:
Income from continuing operations for common stockholders (in usd per share)	$ 0.24	$ 0.44	$ 0.02
Income from discontinued operations for common stockholders (in usd per share)	0.07	0.14	0.20
Net income available to common stockholders (in usd per share)	0.31	0.58	0.22
Per common share information — diluted:
Income from continuing operations for common stockholders (in usd per share)	0.24	0.44	0.02
Income from discontinued operations for common stockholders (in usd per share)	0.07	0.14	0.20
Net income available to common stockholders (in usd per share)	$ 0.31	$ 0.58	$ 0.22
Weighted average shares — basic	253,895	215,827	204,216
Weighted average shares — diluted	256,023	215,979	204,460
Dividends declared per common share (in usd per share)	$ 0.24	$ 0.32	$ 0.3