SIGNIFICANT ACCOUNTING POLICIES - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Purchased intangible assets
Weighted average amortization period	12 years
Gross	$ 57,342	$ 63,078
Accumulated Amortization	(36,924)	(36,344)
Net	20,418	26,734
Expected future amortization of intangible assets
2016	3,956
2017	3,936
2018	2,734
2019	1,538
2020	1,538
Thereafter	6,716
Net	$ 20,418	26,734
Core technology [Member]
Purchased intangible assets
Weighted average amortization period	20 years
Gross	$ 18,524	20,667
Accumulated Amortization	(7,528)	(7,360)
Net	10,996	13,307
Expected future amortization of intangible assets
Net	$ 10,996	13,307
Customer relationships [Member]
Purchased intangible assets
Weighted average amortization period	9 years
Gross	$ 36,830	40,195
Accumulated Amortization	(27,701)	(27,270)
Net	9,129	12,925
Expected future amortization of intangible assets
Net	$ 9,129	12,925
Trademarks / Trade names [Member]
Purchased intangible assets
Weighted average amortization period	9 years
Gross	$ 1,988	2,216
Accumulated Amortization	(1,695)	(1,714)
Net	293	502
Expected future amortization of intangible assets
Net	$ 293	$ 502