Note 10 - Stockholders' Equity (Details Textual) - USD ($)																	3 Months Ended	6 Months Ended	9 Months Ended		19 Months Ended
	Sep. 17, 2021	Sep. 10, 2021	Sep. 08, 2021	Aug. 20, 2021	Jul. 28, 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	Feb. 11, 2020	Jan. 31, 2020	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)														$ 0.01		$ 0.01			$ 0.01		$ 0.01		$ 0.01
Common Stock, Shares, Issued, Total (in shares)																			9,449,083		9,449,083		5,350,000
Common Stock, Shares, Outstanding, Ending Balance (in shares)																		5,498,980	9,162,096		9,162,096	5,022,578	5,022,578
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																	$ 377,000			$ 1,716,000	$ 4,800,000
Treasury Stock Acquired, Average Cost Per Share (in dollars per share)																					$ 14.61
Treasury Stock, Shares, Retired (in shares)							40,435
Treasury Stock, Shares, Ending Balance (in shares)							286,987
Noncontrolling Interest, Shares Redeemed (in shares)			1,479,132
Stock Issued During Period, Shares, Conversion of Redeemable Noncontrolling Interests (in shares)			1,479,132
Common Stock [Member]
Dividends Payable, Amount Per Share (in dollars per share)					$ 0.475
Dividends Payable, Date Declared					Jul. 28, 2021
Dividends Payable, Date to be Paid					Sep. 30, 2021
Dividends Payable, Date of Record					Sep. 15, 2021
Preferred Stock [Member]
Dividends Payable, Amount Per Share (in dollars per share)	$ 0.53125
Dividends Payable, Date Declared	Sep. 17, 2021
Dividends Payable, Date to be Paid	Oct. 25, 2021
Dividends Payable, Date of Record	Oct. 15, 2021
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
Partners' Capital Account, Distribution Per Unit of Limited Partner Interest (in dollars per share)																		$ 30.00
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)																			232,184
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture, Total (in shares)																			67,992
2020 LTIP [Member]
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)								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)								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)									1,838
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
Series A Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)										2,000,000
Underwriting Discount and Commission Expenses										$ 1,200,000
Payments of Stock Issuance Costs										$ 800,000
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
Preferred Stock, Liquidation Preference Per Share (in dollars per share)										$ 25.00	$ 25.00
Treasury Stock, Shares, Acquired (in shares)																		0
IPO [Mmember]
Stock Issued During Period, Shares, New Issues (in shares)															5,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)															$ 0.01
Shares Issued, Price Per Share (in dollars per share)															$ 19.00
Proceeds from Issuance Initial Public Offering															$ 101,700,000
Underwriting Discount and Commission Expenses															6,900,000
Payments of Stock Issuance Costs															$ 3,300,000
IPO [Mmember] | Underwriters [Member]
Stock Issued During Period, Shares, New Issues (in shares)															350,000
Common Stock, Par or Stated Value Per Share (in dollars per share)															$ 0.01
Shares Issued, Price Per Share (in dollars per share)															$ 19.00
At-the-market Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)																			532,694
Payments of Stock Issuance Costs																			$ 693,575
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
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