Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Preferred Stock Public offering of preferred stock	Preferred Stock	Common Stock Underwritten public offering of common stock	Common Stock	Additional Paid-in Capital Underwritten public offering of common stock	Additional Paid-in Capital Public offering of preferred stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit and Distributions	Total Shareholders' Equity Underwritten public offering of common stock	Total Shareholders' Equity Public offering of preferred stock	Total Shareholders' Equity	Non-controlling Interests Operating Partnership	Non-controlling Interests Joint Venture	Underwritten public offering of common stock	Public offering of preferred stock	Total
Balance at beginning of year at Dec. 31, 2012		$ 50		$ 462			$ 468,820	$ (528)	$ (31,985)			$ 436,819	$ 36,718				$ 473,537
Balance (in shares) at Dec. 31, 2012		5,000,000		46,159,652
Changes in equity
Net proceeds from sale of stock	$ 34		$ 345		$ 299,727	$ 81,689				$ 300,072	$ 81,723				$ 300,072	$ 81,723
Sale of stock (in shares)	3,400,000		34,500,000
Common stock redemption of common units				$ 44			30,574					30,618	(30,618)
Common stock redemption of common units (in shares)				4,414,950
Contribution by non-controlling interests in joint venture														$ 7,500			7,500
Dividends paid									(46,470)			(46,470)	(1,124)				(47,594)
Equity-based compensation				$ 3			2,048					2,051	73				2,124
Equity-based compensation (in shares)				327,806
Other comprehensive income (loss)								(851)				(851)	(30)				(881)
Net income (loss)									5,878			5,878	(297)	316			5,897
Balance at end of year at Dec. 31, 2013		$ 84		$ 854			882,858	(1,379)	(72,577)			809,840	4,722	7,816			822,378
Balance (in shares) at Dec. 31, 2013		8,400,000		85,402,408
Changes in equity
Common stock redemption of common units				$ 4			2,425					2,429	(2,429)
Common stock redemption of common units (in shares)				438,631
Common units issued for acquisition													3,685				3,685
Acquisition of non-controlling interest in joint venture							(415)					(415)		(7,817)			(8,232)
Dividends paid									(56,073)			(56,073)	(477)				(56,550)
Equity-based compensation				$ 3			3,479					3,482	42				3,524
Equity-based compensation (in shares)				321,269
Other							(156)					(156)					(156)
Other (in shares)				(12,588)
Other comprehensive income (loss)								(367)				(367)	(4)				(371)
Net income (loss)									20,871			20,871	51	$ 1			20,923
Balance at end of year at Dec. 31, 2014		$ 84		$ 861			888,191	(1,746)	(107,779)			779,611	5,590				785,201
Balance (in shares) at Dec. 31, 2014		8,400,000		86,149,720
Changes in equity
Common stock redemption of common units				$ 3			1,919					1,922	(1,922)
Common stock redemption of common units (in shares)				268,947
Dividends paid									(57,293)			(57,293)	(309)				(57,602)
Equity-based compensation				$ 4			4,713					4,717	36				4,753
Equity-based compensation (in shares)				411,239
Other							(763)					(763)					(763)
Other (in shares)				(36,385)
Other comprehensive income (loss)								80				80	1				81
Net income (loss)									124,437			124,437	819				125,256
Balance at end of year at Dec. 31, 2015		$ 84		$ 868			$ 894,060	$ (1,666)	$ (40,635)			$ 852,711	$ 4,215				$ 856,926
Balance (in shares) at Dec. 31, 2015		8,400,000		86,793,521