Note 2 - Operating Property Activities - Previous Ownership Interest and Gain on Change of Interest (Details) $ in Millions	9 Months Ended
Sep. 30, 2016 USD ($)
Oakwood Plaza [Member]
Previous ownership interest	55.00%
Gain on change in control of interests, net	$ 46.5
Gateway Plaza [Member]
Previous ownership interest	15.00%
Gain on change in control of interests, net
GEPT Portfolio [Member]
Previous ownership interest	15.00%
Gain on change in control of interests, net	$ 6.6
Gain on change in control of interests, net	$ 53.1

In a business combination achieved in stages, this element represents the amount of net gain (loss) recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)(2)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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Period Type:	duration