Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
REVENUES
Rental income	$ 407,481	$ 383,333	$ 361,525
Mortgage interest		91	3,665
Other operating	4,149	5,047	5,665
Total Revenue	411,630	388,471	370,855
EXPENSES
Property operating	146,458	140,195	134,057
General and administrative	35,805	26,925	22,808
Depreciation	116,483	106,530	99,384
Amortization	11,207	10,084	10,820
Bad debt, net of recoveries	(21)	(193)	31
Total Expenses	309,932	283,541	267,100
OTHER INCOME (EXPENSE)
Gain on sales of real estate assets	41,038	56,602	0
Interest Expense	(57,351)	(65,534)	(72,413)
Loss on extinguishment of debt	0	(27,998)	0
Pension termination	(4)	(5,260)	0
Impairment of real estate assets	0	(3,639)	0
Impairment of internally-developed software	0	(654)	0
Interest and other income, net	375	389	2,637
Total other income (expense)	(15,942)	(46,094)	(69,776)
INCOME FROM CONTINUING OPERATIONS	85,756	58,836	33,979
DISCONTINUED OPERATIONS
Income (loss) from discontinued operations	(71)	715	967
Impairments of real estate assets	(121)	(686)	(12,029)
Gain on sales of real estate properties	7	10,571	9,283
INCOME (LOSS) FROM DISCONTINUED OPERATIONS	(185)	10,600	(1,779)
NET INCOME	85,571	69,436	32,200
Less: Net income attributable to noncontrolling interests			(313)
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ 85,571	$ 69,436	$ 31,887
BASIC EARNINGS (LOSS) PER COMMON SHARE:
Income (loss) from continuing operations (in dollars per share)	$ 0.79	$ 0.59	$ 0.35
Discontinued operations (in dollars per share)	0.00	0.11	(0.02)
Net income attributable to common stockholders (in dollars per share)	0.79	0.70	0.33
DILUTED EARNINGS (LOSS) PER COMMON SHARE:
Income (loss) from continuing operations (in dollars per share)	0.78	0.59	0.35
Discontinued operations (in dollars per share)	0.00	0.11	(0.02)
Net income attributable to common stockholders (in dollars per share)	$ 0.78	$ 0.70	$ 0.33
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING - BASIC (in shares)	108,572,102	99,171,352	95,279,226
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING - DILUTED (in shares)	109,386,997	99,880,302	96,759,410