CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($)	Total	Total Stockholders’ Equity	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Distributions in Excess of Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Common Stock	Common Stock Total Stockholders’ Equity	Common Stock Common Stock	Common Stock Additional Paid-in Capital	Series A Preferred Stock	Series A Preferred Stock Total Stockholders’ Equity	Series A Preferred Stock Preferred Stock
Beginning Balance at Dec. 31, 2013	$ 341,769,000	$ 306,198,000	$ 0	$ 255,000	$ 311,936,000	$ (5,993,000)		$ 35,571,000
Beginning Balance, shares at Dec. 31, 2013				25,559,886
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock									$ 232,875,000	$ 232,875,000	$ 172,000	$ 232,703,000
Issuance of common stock, shares											17,250,000
Offering costs	(11,158,000)	(11,158,000)			(11,158,000)
Share-based compensation	1,163,000	1,163,000			1,163,000
Share-based compensation, shares				213,569
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock	(98,000)	(98,000)			(98,000)
Shares acquired to satisfy minimum tax withholding on vesting restricted stock, shares				(6,928)
Conversion of units to common stock	0	7,779,000		$ 7,000	7,772,000			(7,779,000)
Conversion of units to common stock, shares				685,915
Net income	976,000	896,000				896,000		80,000
Other comprehensive income	(1,402,000)	(1,331,000)					$ (1,331,000)	(71,000)
Common stock dividends	16,576,000	16,576,000				16,576,000
Distributions	(1,672,000)							(1,672,000)
Ending Balance at Dec. 31, 2014	545,877,000	519,748,000	0	$ 434,000	542,318,000	(21,673,000)	(1,331,000)	26,129,000
Ending Balance, shares at Dec. 31, 2014				43,702,442
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock	184,007,000	184,007,000		$ 115,000	183,892,000
Issuance of common stock, shares				11,500,500
Offering costs	(8,174,000)	(8,174,000)			(8,174,000)
Share-based compensation	1,852,000	1,765,000		$ 1,000	1,764,000			87,000
Share-based compensation, shares				120,178
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock	(191,000)	(191,000)			(191,000)
Shares acquired to satisfy minimum tax withholding on vesting restricted stock, shares				(12,670)
Conversion of units to common stock	$ 0	3,162,000		$ 3,000	3,159,000			(3,162,000)
Conversion of units to common stock, shares	288,234
Repurchase of operating partnership units	$ (136,000)	(46,000)			(46,000)			(90,000)
Net income	1,950,000	1,874,000				1,874,000		76,000
Other comprehensive income	(1,742,000)	(1,702,000)					(1,702,000)	(40,000)
Common stock dividends	28,304,000	28,304,000				28,304,000
Distributions	(1,395,000)							(1,395,000)
Ending Balance at Dec. 31, 2015	$ 693,744,000	672,139,000	0	$ 553,000	722,722,000	(48,103,000)	(3,033,000)	21,605,000
Ending Balance, shares at Dec. 31, 2015	55,598,684			55,598,684
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock									$ 191,990,000	$ 191,990,000	$ 108,000	$ 191,882,000	$ 90,000,000	$ 90,000,000	$ 90,000,000
Issuance of common stock, shares											10,752,683
Offering costs	$ (12,011,000)	(12,011,000)	(3,349,000)		(8,662,000)
Share-based compensation	3,982,000	2,010,000		$ 1,000	2,009,000			1,972,000
Share-based compensation, shares				79,736
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock	(747,000)	(747,000)			(747,000)
Shares acquired to satisfy minimum tax withholding on vesting restricted stock, shares				(36,374)
Conversion of units to common stock	$ 0	630,000		$ 0	630,000			(630,000)
Conversion of units to common stock, shares	59,646
Acquisition of real estate portfolio	$ 125,000							125,000
Net income	25,876,000	25,126,000	1,983,000			23,143,000		750,000
Other comprehensive income	6,693,000	6,478,000					6,478,000	215,000
Preferred stock dividends	(1,983,000)	(1,983,000)	(1,983,000)			0
Common stock dividends	34,317,000	34,317,000				34,317,000
Distributions	(1,212,000)							(1,212,000)
Ending Balance at Dec. 31, 2016	$ 962,140,000	$ 939,315,000	$ 86,651,000	$ 662,000	$ 907,834,000	$ (59,277,000)	$ 3,445,000	$ 22,825,000
Ending Balance, shares at Dec. 31, 2016	66,454,375			66,454,375