Note 3 - Operating Property Activities - Disposition Activity (Details) $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Gain on sale of properties/change in control of interests	$ 38.4	$ 152.2
Disposition Activity Relating to Consolidated Operating Properties and Parcels [Member]
Aggregate sales price/gross fair value	$ 110.1	$ 833.1
Number of operating properties sold/deconsolidated	7	35
Number of out-parcels sold	5	2

Amount after tax of gain (loss) not previously recognized resulting from the disposal of a discontinued operation.

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