OTHER INTANGIBLE ASSETS (NARRATIVE) (DETAILS) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted Average Useful Life [Line Items]
Amortization expense related to intangible assets									$ 7,467,000	$ 9,531,000
Impairment losses	$ 5,322,000	$ 0	$ 0	$ 0	$ 26,448,000	$ 5,602,000	$ 0	$ 0	5,322,000	32,050,000	$ 8,100,000
CTS - Avaya
Weighted Average Useful Life [Line Items]
Impairment of Intangible Assets, Finite-lived					900,000	400,000
Impairment losses					11,300,000	$ 700,000
CSS - component held-for-sale
Weighted Average Useful Life [Line Items]
Amortization expense related to intangible assets									7,500,000	$ 9,500,000	$ 9,700,000
Customer Relationships
Weighted Average Useful Life [Line Items]
Amortization expense related to intangible assets									$ 0
Customer Relationships | CTS - Avaya
Weighted Average Useful Life [Line Items]
Impairment losses					9,200,000
Customer Relationships | CSS - component held-for-sale
Weighted Average Useful Life [Line Items]
Weighted average useful life of intangible assets									8 years 9 months 18 days
Trade Names
Weighted Average Useful Life [Line Items]
Amortization expense related to intangible assets									$ 0
Trade Names | CTS - eLoyalty
Weighted Average Useful Life [Line Items]
Impairment of Intangible Assets, Finite-lived	0
Impairment losses	3,300,000
Trade Names | CSS - PRG
Weighted Average Useful Life [Line Items]
Impairment losses	$ 2,000,000
Trade Names | CTS - Avaya
Weighted Average Useful Life [Line Items]
Impairment losses					400,000
Trade Names | CSS - rogenSi
Weighted Average Useful Life [Line Items]
Estimated royalty rate						2.00%
Growth rate						3.00%
Discount rate						18.20%
Impairment of Intangible Assets, Finite-lived					0	$ 3,100,000
Impairment losses					3,000,000	$ 1,200,000
Trade Names | CSS - component held-for-sale
Weighted Average Useful Life [Line Items]
Estimated royalty rate						3.75%
Growth rate						3.00%
Discount rate						19.20%
Impairment of Intangible Assets, Finite-lived						$ 2,000,000
Impairment losses						$ 3,300,000
Trade Names | Technology Solutions Group | CTS - Avaya
Weighted Average Useful Life [Line Items]
Estimated royalty rate						0.50%
Growth rate						3.00%
Discount rate						19.00%
Other Intangible Assets
Weighted Average Useful Life [Line Items]
Amortization expense related to intangible assets									$ 0
Other Intangible Assets | CSS - component held-for-sale
Weighted Average Useful Life [Line Items]
Weighted average useful life of intangible assets									3 years 9 months 18 days
Non-compete intangible assets | CTS - Avaya
Weighted Average Useful Life [Line Items]
Impairment losses					400,000
Fixed Assets | CTS - Avaya
Weighted Average Useful Life [Line Items]
Impairment losses					$ 1,300,000