Note 4 - Investments in and Advances to Real Estate Joint Ventures (Details Textual) ft² in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017 USD ($) ft²	Mar. 31, 2016 USD ($)	Dec. 31, 2016 ft²
Gross Leasable Area | ft²	[1]	411
Business Combination, Consideration Transferred		$ 59,563
All Equity Method Investments [Member]
Gross Leasable Area | ft²		25,300		26,200
Kim Pru and Kim Pru II [Member]
Number of Joint Ventures		4
Number Of Accounts		4
Kim Pru [Member]
Number of Joint Ventures		3
Real Estate Joint Ventures [Member] | Operating Properties [Member]
Number of Real Estate Properties, Interest Disposed of or Transferred		5
Equity Method Investment, Sales Price		$ 47,700
Equity Method Investment, Realized Gain (Loss) on Disposal		$ 900	$ 54,100
Number of Real Estate Properties, Remaining Interest Acquired		2	9
Business Combination, Consideration Transferred		$ 15,400	$ 344,500

[1] Gross leasable area ("GLA")