Note 4 - Dispositions of Real Estate - Disposition Activity (Details) $ in Millions		12 Months Ended
		Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Aggregate sales price/gross fair value (1) (2) (3)	[1],[2],[3]	$ 214.2	$ 191.1	$ 612.4
Number of operating properties sold/deconsolidated (1) (3)	[1],[2]	6	9	13
Disposition Activity Relating to Consolidated Operating Properties and Parcels [Member]
Gain on sale of properties (3) (4)	[1],[4]	$ 75.0	$ 15.2	$ 30.8
Number of parcels sold		13	13	10

[1] During 2021, the Company purchased its partner’s 70.0% remaining interest in Jamestown Portfolio, which is comprised of six property interests. The Company then entered into a joint venture with Blackstone Real Estate Income Trust, Inc. (“BREIT”) in which it contributed these six properties for a gross sales price of $425.8 million, including $170.0 million of non-recourse mortgage debt. As a result, the Company no longer consolidates these six property interests and recognized a loss on change in control of interests of $0.4 million. The Company has a 50.0% investment in this joint venture ($130.1 million as of the date of deconsolidation), included in Investments in and advances to real estate joint ventures on the Company’s Consolidated Balance Sheets.

[2] During 2023, the Company contributed a land parcel and related entitlements, located in Admore, PA, into a preferred equity investment with a gross value of $19.6 million. As a result, the Company no longer consolidates this land parcel and has a non-controlling interest in this investment. See Footnote 7 of the Notes to the Company’s Consolidated Financial Statements for preferred equity investment disclosure.

[3] During 2023, the Company provided as a lender seller financing of $25.0 million related to the sale of an operating property located in Gresham, OR. See Footnote 11 of the Notes to the Company’s Consolidated Financial Statements for mortgage receivable loan disclosure.

[4] For the years ended December 31, 2023, 2022 and 2021 amounts are before noncontrolling interests of $1.8 million, $1.7 million, and $3.0 million respectively and taxes of $1.6 million, $1.2 million and $2.2 million, respectively, after utilization of net operating loss carryforwards.