Note 3 - Property Acquisitions, Developments and Other Investments - Acquisition of Operating Properties (Details) ft² in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2020 USD ($) ft²	Dec. 31, 2019 USD ($) ft²
Purchase Price GLA (Square Foot) | ft²			290
Purchase Price Cash	[1]		$ 33,226
Purchase Price Total			43,158
Purchase Price Debt Acquired			5,389
Purchase Price Other	[2]		$ 4,543
Bell Camino Out-parcel [Member]
Purchase Price GLA (Square Foot) | ft²			45
Purchase Price Cash	[1]		$ 5,678
Purchase Price Total			$ 5,678
Gateway at Donner Pass Out-parcel [Member]
Purchase Price GLA (Square Foot) | ft²			40
Purchase Price Cash	[1]		$ 13,527
Purchase Price Total			$ 13,527
Rancho Penasquitos Out-parcel [Member]
Purchase Price GLA (Square Foot) | ft²			40
Purchase Price Cash	[1]		$ 12,064
Purchase Price Total			$ 12,064
Linwood Square [Member]
Purchase Price GLA (Square Foot) | ft²	[3]		165
Purchase Price Cash	[1],[3]		$ 1,957
Purchase Price Total	[3]		11,889
Purchase Price Debt Acquired	[3]		5,389
Purchase Price Other	[2],[3]		$ 4,543
North Valley Parcel [Member]
Purchase Price Cash		$ 7,073
Purchase Price GLA (Square Foot) | ft²	[4]	9

[1] The Company utilized an aggregate $36.1 million associated with Internal Revenue Code 26 U.S.C. §1031 sales proceeds.

[2] Includes the Company's previously held equity interest investment, net of noncontrolling interest of the remaining partners.

[3] The Company acquired a partner's ownership interest in a property which was held in a joint venture in which the Company had a noncontrolling interest. The Company now has a 69.5% controlling interest in this property and has deemed this entity to be a VIE for which the Company is the primary beneficiary and consolidates the asset. The Company evaluated this transaction pursuant to the FASB's Consolidation guidance and, as a result, recognized a gain on change in control of interests of $0.1 million resulting from the fair value adjustment associated with the Company’s previously held equity interest, which are included in the purchase price above in Other Consideration.

[4] Gross leasable area ("GLA")