ACQUISITIONS (Intangible Assets) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
2015 Acquisitions | NavigationArts
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 2,800
2015 Acquisitions | AGS
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 22,700
2015 Acquisitions | Customer relationships | NavigationArts
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Finite-lived Intangible Assets Acquired	$ 2,800
2015 Acquisitions | Customer relationships | AGS
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Finite-lived Intangible Assets Acquired	$ 22,700
2014 Acquisition | Netsoft
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	1,700
2014 Acquisition | Jointech
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	15,312
2014 Acquisition | GGA
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	16,000
2014 Acquisition | Great Fridays
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 200
2014 Acquisition | Customer relationships | Netsoft
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Finite-lived Intangible Assets Acquired	$ 1,700
2014 Acquisition | Customer relationships | Jointech
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Finite-lived Intangible Assets Acquired	$ 15,000
2014 Acquisition | Customer relationships | GGA
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Finite-lived Intangible Assets Acquired	$ 16,000
2014 Acquisition | Customer relationships | Great Fridays
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Finite-lived Intangible Assets Acquired	$ 200
2014 Acquisition | Trade names | Jointech
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Finite-lived Intangible Assets Acquired	$ 312