MANAGEMENT SERVICES BUSINESS - General Information (Details)		3 Months Ended		9 Months Ended		12 Months Ended			58 Months Ended
	Nov. 26, 2019 USD ($) property shares	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) shares	Dec. 12, 2023 USD ($)	Feb. 16, 2023 USD ($)	Oct. 26, 2021 USD ($)
Real Estate
Investment in Alpine Income Property Trust, Inc.		$ 42,997,000		$ 42,997,000		$ 39,445,000			$ 42,997,000
Revenues		31,805,000	$ 28,470,000	88,777,000	$ 79,234,000
Management Fee Income
Real Estate
Revenues		1,124,000	1,094,000	3,360,000	$ 3,294,000
Management Fee Income | Portfolio Management Agreement
Real Estate
Revenues				200,000
Management Fee Income | Portfolio Management Agreement | Maximum
Real Estate
Revenues		100,000
Management Fee Income | Asset Management Agreement
Real Estate
Revenues				$ 100,000
Management Fee Income | Asset Management Agreement | Maximum
Real Estate
Revenues		$ 100,000
Alpine Income Property OP, LP Limited Partnership Units
Real Estate
Number of contributed properties | property	5
Aggregate of OP units | shares	1,223,854
Initial value	$ 23,300,000
Share purchased | shares									1,223,854
Investment ownership percentage (as a percent)		7.90%		7.90%					7.90%
Investment in Alpine Income Property Trust, Inc.		$ 22,274,000		$ 22,274,000		20,695,000			$ 22,274,000
Alpine Income Property Trust, Inc. Common Stock and Alpine Income Property OP, LP Limited Partnership Units
Real Estate
Investment ownership percentage (as a percent)		15.30%		15.30%					15.30%
Investment in Alpine Income Property Trust, Inc.		$ 42,997,000		$ 42,997,000		39,445,000			$ 42,997,000
Common Stock
Real Estate
Share purchased | shares	421,053			29,807	129,271		155,665	8,088	1,138,621
Purchase price of shares	$ 8,000,000.0			$ 400,000	$ 2,100,000		$ 2,700,000	$ 100,000
Investment ownership percentage (as a percent)		7.40%		7.40%					7.40%
Investment in Alpine Income Property Trust, Inc.		$ 20,723,000		$ 20,723,000		18,750,000			$ 20,723,000
Private placement
Real Estate
Share purchased | shares	394,737
Purchase price of shares	$ 7,500,000
Management Agreement PINE
Real Estate
Percentage of base management fee				0.375%
Management fee (as a percent)				1.50%
Percentage of cumulative annual hurdle rate				8.00%
Amount of threshold incentive fee				$ 0.00
Percentage of multiply factor				15.00%
Management fee revenue earned		1,100,000	1,100,000	$ 3,100,000	3,300,000
Dividends received		700,000	$ 600,000	1,900,000	$ 1,900,000
Alpine
Real Estate
Number of properties sold | property	15
Aggregate cash consideration	$ 125,900,000
Amount of shares authorized for purchase by the board		$ 0		$ 0					$ 0	$ 2,000,000.0	$ 2,100,000	$ 5,000,000.0
Average price per share | $ / shares				$ 14.97	$ 16.21		$ 17.57	$ 17.65
Investee | Alpine Income Property Trust, Inc.
Real Estate
Incentive fee income						$ 0