SEGMENT INFORMATION (Financial Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 4,281,105	$ 4,598,161	$ 3,771,170
Consolidated Adjusted EBITDA	57,548	60,549	77,995
Depreciation and amortization expense	10,892	9,838	6,248
Impairment expense	9,203
Stock compensation expense	43,178	30,861	24,493
Stock option expense	10,736	14,442	13,102
Operating profit	(16,461)	5,408	34,152
Goodwill	16,982	27,212	12,945
Corporate expenses and other
Segment Reporting Information [Line Items]
Consolidated Adjusted EBITDA	(10,376)	(16,756)	(13,708)
Operating segments | North American Realty
Segment Reporting Information [Line Items]
Revenues	4,220,063	4,552,938	3,745,354
Consolidated Adjusted EBITDA	91,101	103,255	116,800
Goodwill	14,595	16,577
Operating segments | International Realty
Segment Reporting Information [Line Items]
Revenues	53,931	35,924	17,804
Consolidated Adjusted EBITDA	(13,657)	(13,708)	(9,138)
Operating segments | Virbela
Segment Reporting Information [Line Items]
Revenues	7,284	8,485	8,615
Consolidated Adjusted EBITDA	(5,725)	(9,642)	(12,637)
Goodwill		8,248
Operating segments | Other Affiliated Services
Segment Reporting Information [Line Items]
Revenues	4,802	5,084	2,896
Consolidated Adjusted EBITDA	(3,795)	(2,600)	(3,322)
Goodwill	2,387	2,387
Segment eliminations
Segment Reporting Information [Line Items]
Revenues	$ (4,975)	$ (4,270)	$ (3,499)