CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Rental income	$ 69,296	$ 63,611
Expenses:
Real estate taxes	8,177	7,653
Utility expenses	4,606	4,174
Other operating expenses	13,992	12,911
Depreciation and amortization	20,505	18,324
Acquisition related costs	0	152
General and administrative	3,962	3,526
Total expenses	51,242	46,740
Operating income	18,054	16,871
Dividend income	304	0
Interest income	61	6
Interest expense (including net amortization of debt premiums and discounts and debt issuance costs of $807 and $471, respectively)	(13,581)	(9,364)
Gain on early extinguishment of debt	0	104
Income from continuing operations before income taxes and equity in earnings of investees	4,838	7,617
Income tax expense	(18)	(15)
Equity in earnings of investees	2,739	9,934
Income from continuing operations	7,559	17,536
Loss from discontinued operations	(144)	(149)
Net income	7,415	17,387
Other comprehensive income
Unrealized gain on investment in available for sale securities	12,142	12,871
Equity in unrealized gain of investees	4,615	4,544
Other comprehensive income	16,757	17,415
Comprehensive income	$ 24,172	$ 34,802
Weighted average common shares outstanding (basic) (in shares)	71,079	71,031
Weighted average common shares outstanding (diluted) (in shares)	71,094	71,031
Per common share amounts (basic and diluted):
Income from continuing operations (in dollars per share)	$ 0.11	$ 0.25
Loss from discontinued operations (in dollars per share)	0.00	0.00
Net income (in dollars per share)	$ 0.10	$ 0.24