ACQUISITIONS AND DISPOSALS (Summary of Estimated Useful lives of Intangible Assets Acquired ) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Apr. 03, 2017	Feb. 28, 2017	Feb. 09, 2015
Turnstyle Analytics Inc
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned		$ 4,252
Useful Life	4 years 10 months 24 days
Turnstyle Analytics Inc | Acquired technology
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned		3,250
Useful Life	5 years
Turnstyle Analytics Inc | Business relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned		672
Useful Life	5 years
Turnstyle Analytics Inc | Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned		250
Useful Life	3 years
Turnstyle Analytics Inc | User relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned		$ 80
Useful Life	3 years
Nowait, Inc
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			$ 12,670
Useful Life	9 years 7 months 6 days
Nowait, Inc | Enterprise restaurant relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			8,500
Useful Life	12 years
Nowait, Inc | Acquired technology
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			2,900
Useful Life	5 years
Nowait, Inc | Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			610
Useful Life	3 years
Nowait, Inc | Local restaurant relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			600
Useful Life	5 years
Nowait, Inc | User relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned			$ 60
Useful Life	3 years
Eat 24
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned				$ 39,600
Useful Life	8 years 7 months 6 days
Eat 24 | Restaurant relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned				17,400
Useful Life	12 years
Eat 24 | Acquired technology
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned				7,400
Useful Life	5 years
Eat 24 | User relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned				12,000
Useful Life	7 years
Eat 24 | Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Amount Assigned				$ 2,800
Useful Life	4 years