Note 7 - Goodwill and Other Acquired Intangible Assets, Net - Interim Impairment Analysis (Details) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Real Estate segment
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill and Intangible Asset Impairment	$ 0.0

Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

No definition available.

Name:	us-gaap_GoodwillAndIntangibleAssetImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration