SALE OF BUSINESS (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Business					$ 0	$ (537)
Hospitality [Member]
Segment Reporting Information [Line Items]
Proceeds from Divestiture of Businesses			$ 16,500
Divestiture of business selling costs			1,500
Escrow Deposits Related to Property Sales	$ 1,700		1,700
Proceeds from Divesture of Business, Receivable, Working Capital	200		200
Net Cash Provided by (Used in) Discontinued Operations			14,000
Proceeds from Divesture of Business, Receivable, Working Capital			$ (800)
Gain (Loss) on Disposition of Business	500
Escrow Deposit Disbursements Related to Property Acquisition	700
Rigzone [Member]
Segment Reporting Information [Line Items]
Proceeds from Divestiture of Businesses				$ 4,200
Divestiture of business selling costs				600
Escrow Deposits Related to Property Sales		$ 400
Proceeds from Divesture of Business, Receivable, Working Capital				4,600
Disposal Group, Including Discontinued Operation, Deferred Revenue				1,200
Health eCareers [Member]
Segment Reporting Information [Line Items]
Proceeds from Divestiture of Businesses				15,000
Divestiture of business selling costs				$ 600
Escrow Deposits Related to Property Sales	$ 1,500