Capital (Details) - USD ($)			3 Months Ended							9 Months Ended		40 Months Ended
		Jun. 17, 2021	Sep. 30, 2021	Jun. 30, 2021		Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Dec. 31, 2020	Jun. 13, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized			500,000,000							500,000,000		500,000,000	500,000,000
Common stock par value			$ 0.01							$ 0.01		$ 0.01	$ 0.01
Preferred stock authorized			100,000,000							100,000,000		100,000,000	100,000,000
Preferred stock par value			$ 0.01							$ 0.01		$ 0.01	$ 0.01
Preferred shares issued			0							0		0	0
Common Stock, Dividends, Per Share, Declared			$ 0.30				$ 0.28			$ 0.88	$ 0.84
Dividends	[1]		$ (3,881,000)	$ (3,876,000)		$ (3,456,000)	$ (3,454,000)	$ (3,450,000)	$ (3,449,000)
Stock Issued During Period, Shares, Restricted Stock Award, Gross			16,816				15,020			16,816	15,020
Common Stock, Capital Shares Reserved for Future Issuance			275,232							275,232		275,232	274,798
Stock Repurchase Program, Authorized Amount														1,200,000
Repurchase of common shares, shares			0				0			0	(136,142)	(434,171)
Repurchase of common shares, Value									$ (986,000)		$ (1,000,000)	$ (4,100,000)
Stock Repurchases Average Price Per Share											$ 7.24	$ 9.45
Intended Distribution of Taxable Net Income, Percentage on Annual Basis										100.00%
Shares Issued, Shares		575,000	0				0			575,000	0
Common shares, par value $0.01 per share, 500,000,000 shares authorized; (12,935,358 and 12,343,542 shares issued and outstanding, respectively)		$ 7,100,000		$ 7,060,000	[2]
Total number of shares included in follow on offering		3,250,000
Shares sold by affiliate		$ 2,675,000
Vest December 13, 2021 [Member] | Partially dedicated employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross										3,668

[1] For the three-month periods ended September 30, 2021 and 2020, dividends totaling $0.30 and $0.28, respectively, per common share outstanding, were declared. For the nine-month periods ended September 30, 2021 and 2020, dividends totaling $0.88 and $0.84, respectively, per common share outstanding, were declared.

[2] Net of underwriters' discounts and commissions and offering costs.