Note 11 - Stockholders' Equity (Details Textual) - USD ($)																		3 Months Ended		22 Months Ended
	Feb. 21, 2022	Feb. 14, 2022	Jan. 07, 2022	Nov. 08, 2021	Sep. 10, 2021	Sep. 08, 2021	Aug. 20, 2021	Apr. 01, 2021	Mar. 03, 2021	Feb. 22, 2021	Nov. 02, 2020	Jul. 24, 2020	Jul. 20, 2020	Jun. 24, 2020	May 08, 2020	Mar. 09, 2020	Jan. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Mar. 15, 2022
Common Stock, Shares, Issued (in shares)																		14,772,261		9,450,921
Common Stock, Shares, Outstanding, Ending Balance (in shares)																		14,485,274		9,163,934
Common Stock, Par or Stated Value Per Share (in dollars per share)																$ 0.01	$ 0.01	$ 0.01		$ 0.01
Stock Repurchase Program, Authorized Amount																$ 10,000,000.0
Stock Repurchase Program, Period in Force (Year)																2 years
Treasury Stock, Shares, Acquired (in shares)																				327,422
Treasury Stock, Value, Acquired, Cost Method																				$ 4,800,000
Treasury Stock Acquired, Average Cost Per Share (in dollars per share)																				$ 14.61
Stock Repurchased and Retired During Period, Shares (in shares)									40,435
Treasury Stock, Shares, Ending Balance (in shares)									286,987
Stock issuance Agreement, Number of Shares (in shares)						13,578,905.9														13,758,905.9
Noncontrolling Interest, Shares Redeemed (in shares)		395,033	4,774,572			1,479,132
Stock Issued During Period, Shares, Conversion of Redeemable Noncontrolling Interests (in shares)		395,033	4,774,570			1,479,132
Common Stock, Dividends, Per Share, Declared (in dollars per share)																		0.5000	$ 0.4750
Common Stock [Member]
Dividends Payable, Amount Per Share (in dollars per share)																		$ 0.53125
Dividends Payable, Date Declared																		Feb. 21, 2022
Dividends Payable, Date to be Paid																		Mar. 31, 2022
Dividends Payable, Date of Record																		Mar. 15, 2022
Preferred Stock [Member]
Dividends Payable, Date Declared																		Mar. 18, 2022
Dividends Payable, Date to be Paid																		Apr. 25, 2022
Dividends Payable, Date of Record																		Apr. 14, 2022
NREF OP IV REIT [Member]
Sale of Stock, Number of Shares Issued in Transaction (in shares)								125
Sale of Stock, Price Per Share (in dollars per share)								$ 1,000
Sale of Stock, Consideration Received on Transaction								$ 100,000
Preferred Units, Distribution Per Year Rate								12.00%
Preferred Units, Purchase Price (in dollars per share)								$ 1,000
Preferred Units, Redemption Value Per Share (in dollars per share)								$ 1,000
Restricted Stock Units (RSUs) [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total (in shares)	60,309
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)																		276,940
Series A Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)												2,000,000
Preferred Stock, Dividend Rate, Percentage												8.50%	8.50%
Preferred Stock, Redemption Price Per Share (in dollars per share)												$ 24.00
Proceeds from Issuance of Preferred Stock and Preference Stock												$ 48,000,000.0
Underwriting Discount and Commission Expenses												1,200,000
Payments of Stock Issuance Costs												$ 800,000
Preferred Stock, Liquidation Preference Per Share (in dollars per share)												$ 25.00	$ 25.00
Series A Preferred Stock [Member] | Preferred Stock [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total (in shares)																		0
Stock Issued During Period, Shares, Conversion of Redeemable Noncontrolling Interests (in shares)																		0
The 2022 At The Market Program (ATM) [Member]
Stock Issued During Period, Shares, New Issues (in shares)																		91,428
Payments of Stock Issuance Costs																		$ 208,873
Equity Distribution Agreements, Maximum Aggregate Sales Price																					$ 100,000,000.0
Shares Issued, Price Per Share (in dollars per share)																		$ 22.44
At-the-market Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)																		532,694
Payments of Stock Issuance Costs																		$ 793,779
Equity Distribution Agreements, Maximum Aggregate Sales Price																			$ 100,000,000.0
At-the-market Offering [Member] | Series A Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)																		0
At-the-market Offering [Member] | Series A Preferred Stock [Member] | Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)																		0
Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)							2,000,000
Shares Issued, Price Per Share (in dollars per share)							$ 21.00
Over-Allotment Option [Member]
Stock Issued During Period, Shares, New Issues (in shares)					59,700		300,000
2020 LTIP [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total (in shares)																		60,309
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period (in shares)																	1,319,734
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)																		4 years
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)	12,464									11,832					14,739
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member] | Officers and Other Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)	264,476									220,352				274,274
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member] | General Partner of Subsidiary [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)				1,201							1,838
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)																		3 years
2020 LTIP [Member] | Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)																		5 years