Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid- in capital	Distributions in excess of earnings	Accumulated other comprehensive loss	Total stockholders’ equity (deficit)	Noncontrolling interests
Beginning balance (in shares) at Dec. 31, 2014		25,022,701
Beginning balance at Dec. 31, 2014	$ 161,906	$ 250	$ 51,472	$ (54,413)	$ 0	$ (2,691)	$ 164,597
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,183			19,642		19,642	11,541
Unrealized cash flow hedge losses	(1,075)				(665)	(665)	(410)
Realized cash flow hedge losses reclassified to net income	27				17	17	10
Net proceeds from sale of common stock (in shares)		4,560,049
Net proceeds from sale of common stock	46,035	$ 45	45,990			46,035
Restricted stock award (in shares)		78,109
Restricted stock awards	993	$ 1	992			993
Acquisitions of real estate investments (in shares)		415,500
Acquisitions of real estate investments	15,169	$ 4	4,429			4,433	10,736
Exchange of owners’ equity for common units	(241)		23			23	(264)
Dividends and distributions declared	(28,277)			(18,239)		(18,239)	(10,038)
Ending balance (in shares) at Dec. 31, 2015		30,076,359
Ending balance at Dec. 31, 2015	225,720	$ 300	102,906	(53,010)	(648)	49,548	176,172
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	42,755			28,074		28,074	14,681
Unrealized cash flow hedge losses	0
Realized cash flow hedge losses reclassified to net income	0
Dedesignation of cash flow hedge	1,048				648	648	400
Net proceeds from sale of common stock (in shares)		5,312,855
Net proceeds from sale of common stock	67,022	$ 53	66,969			67,022
Restricted stock award (in shares)		101,147
Restricted stock awards	1,162	$ 1	1,161			1,162
Acquisitions of real estate investments (in shares)		2,000,000
Acquisitions of real estate investments	47,278	$ 20	26,080			26,100	21,178
Redemption of operating partnership units	(58)		(2)			(2)	(56)
Dividends and distributions declared	$ (35,949)			(24,409)		(24,409)	(11,540)
Ending balance (in shares) at Dec. 31, 2016	37,490,361	37,490,361
Ending balance at Dec. 31, 2016	$ 348,978	$ 374	197,114	(49,345)	0	148,143	200,835
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	29,925			21,047		21,047	8,878
Unrealized cash flow hedge losses	0
Realized cash flow hedge losses reclassified to net income	0
Net proceeds from sale of common stock (in shares)		7,350,690
Net proceeds from sale of common stock	91,381	$ 74	91,307			91,381
Restricted stock award (in shares)		97,173
Restricted stock awards	1,443	$ 1	1,442			1,443
Restricted stock award forfeitures (in shares)		(461)
Restricted stock award forfeitures	(2)		(2)			(2)
Acquisitions of real estate investments	(511)		(1,493)			(1,493)	982
Redemption of operating partnership units	(5,155)		(961)			(961)	(4,194)
Dividends and distributions declared	$ (45,776)			(32,868)		(32,868)	(12,908)
Ending balance (in shares) at Dec. 31, 2017	44,937,763	44,937,763
Ending balance at Dec. 31, 2017	$ 420,283	$ 449	$ 287,407	$ (61,166)	$ 0	$ 226,690	$ 193,593