Note 7 - Goodwill and Other Acquired Intangible Assets, Net - Schedule of Acquired Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 13,241
Real Estate Segment
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	52,778	$ 52,928
Finite-Lived Intangible Assets, Accumulated Amortization	(39,537)	(34,543)
Finite-Lived Intangible Assets, Net	13,241	18,385
Real Estate Segment | Client relationships
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	43,550	43,550
Finite-Lived Intangible Assets, Accumulated Amortization	(31,559)	(27,269)
Finite-Lived Intangible Assets, Net	11,991	16,281
Real Estate Segment | Technology
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8,285	8,435
Finite-Lived Intangible Assets, Accumulated Amortization	(7,370)	(6,789)
Finite-Lived Intangible Assets, Net	915	1,646
Real Estate Segment | Licenses
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	463	463
Finite-Lived Intangible Assets, Accumulated Amortization	(128)	(81)
Finite-Lived Intangible Assets, Net	335	382
Real Estate Segment | Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	480	480
Finite-Lived Intangible Assets, Accumulated Amortization	(480)	(404)
Finite-Lived Intangible Assets, Net	$ 0	$ 76