Consolidated Statements of Changes in Equity and Other Comprehensive Income - USD ($) $ in Thousands	Common stock	Additional Paid-in Capital	Retained Earnings	Cumulative Dividends	Other Comprehensive Income.	Non-controlling Interest in Operating Partnership	Total
Balance at Dec. 31, 2017	$ 329	$ 350,147	$ 5,161	$ (31,199)		$ 46,513	$ 370,951
Balance (in shares) at Dec. 31, 2017	33,334,000
Increase (decrease) in shareholders' equity
Net income			4,940			701	5,641
Issuance of stock under the at-the-market offering, net of costs of $219		(219)					(219)
Grant of unvested restricted stock (in shares)	160,000
Forfeiture of unvested restricted stock (in shares)	(6,000)
Stock based compensation		1,134					1,134
Dividends and distributions accrued or paid			(9,423)	(9,966)		(1,397)	(20,786)
Derivative Liability					$ (173)		(173)
Conversion of Common units to shares of common stock	$ 2	1,543				(1,545)
Conversion of Common units to shares of common stock (in shares)	157,000
Repurchase and cancellation of shares	$ (20)	(14,272)					(14,292)
Repurchase and cancellation of shares (in shares)	(1,949,000)
Adjustments to non-controlling interest resulting from changes in ownership of operating Partnership		642				(642)
Balance at Sep. 30, 2018	$ 311	338,975	678	(41,165)	(173)	43,630	342,256
Balance (in shares) at Sep. 30, 2018	31,696,000
Balance at Dec. 31, 2017	$ 329	350,147	5,161	(31,199)		46,513	370,951
Balance (in shares) at Dec. 31, 2017	33,334,000
Increase (decrease) in shareholders' equity
Issuance of stock (in shares)	157,393
Balance at Dec. 31, 2018	$ 300	332,996	4,852	(42,695)	(865)	44,685	339,273
Balance (in shares) at Dec. 31, 2018	30,594,000
Increase (decrease) in shareholders' equity
Net income			4,695			375	5,070
Issuance of stock		(218)					(218)
Issuance of stock (in shares)	2,678,187
Grant of unvested restricted stock (in shares)	224,000
Forfeiture of unvested restricted stock	$ (1)	(98)					(99)
Forfeiture of unvested restricted stock (in shares)	(21,000)
Stock based compensation		1,259					1,259
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	2,000
Dividends and distributions accrued or paid			(9,368)	(4,573)		(335)	(14,276)
Conversion of Common units to shares of common stock	$ 27	26,217				(26,244)
Conversion of Common units to shares of common stock (in shares)	2,678,000
Net change associated with current period hedging transactions					(950)		(950)
Repurchase and cancellation of shares	$ (34)	(21,146)					(21,180)
Repurchase and cancellation of shares (in shares)	(3,401,000)
Adjustments to non-controlling interest resulting from changes in ownership of operating Partnership		(219)				219
Balance at Sep. 30, 2019	$ 292	$ 338,791	$ 179	$ (47,268)	$ (1,815)	$ 18,700	$ 308,879
Balance (in shares) at Sep. 30, 2019	30,076,000