ACQUISITIONS AND DISPOSALS (Summary of Purchase Price and Net Assets Acquired) (Details) - USD ($) $ in Thousands	Apr. 03, 2017	Feb. 28, 2017	Feb. 09, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combination, Consideration Transferred [Abstract]
Held in escrow account				$ 28,750	$ 0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill				107,954	$ 170,667	$ 172,197
Turnstyle Analytics Inc
Business Combination, Consideration Transferred [Abstract]
Cash consideration	$ 16,648
Held in escrow account	3,093
Total purchase price	19,741
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents	30
Intangible assets	4,252
Goodwill	16,048
Other assets	250
Total assets acquired	20,580
Deferred tax liability	(450)
Other liabilities	(389)
Total liabilities assumed	(839)
Net assets acquired	$ 19,741
Nowait, Inc
Business Combination, Consideration Transferred [Abstract]
Cash consideration		$ 31,892
Held in escrow account		7,945
Total purchase price		39,837
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents		1,004
Intangible assets		12,670
Goodwill		25,959
Other assets		1,065
Total assets acquired		40,698
Other liabilities		(861)
Total liabilities assumed		(861)
Net assets acquired		$ 39,837
Eat 24
Business Combination, Consideration Transferred [Abstract]
Cash consideration			$ 75,000
Held in escrow account				$ 1,900
Contingent consideration			1,876
Fair value of common stock			59,200
Total purchase price			134,158
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents			1,578
Intangible assets			39,600
Goodwill			110,927
Other assets			6,031
Total assets acquired			158,136
Deferred tax liability			(15,207)
Other liabilities			(8,771)
Total liabilities assumed			(23,978)
Net assets acquired			134,158
Distributed | Eat 24
Business Combination, Consideration Transferred [Abstract]
Cash consideration			56,624
Fair value of common stock			46,143
Escrow account | Eat 24
Business Combination, Consideration Transferred [Abstract]
Cash consideration			16,500
Held in escrow account			16,500
Fair value of common stock			$ 13,015