COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2015 USD ($) yr	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Future minimum lease commitments under non-cancelable leases [Abstract]
2016	$ 17,825
2017	14,135
2018	11,116
2019	11,042
2020	7,200
Thereafter	6,713
Total	68,031
Operating Lease Commitments [Abstract]
Restructuring Reserve	7,180	$ 2,343	$ 8,501	$ 8,501	$ 15,731
Rent expense under operating leases, net of operating subleases	14,000	15,000	16,300
Operating Leases, Income Statement, Sublease Revenue	600			700
Contingencies [Abstract]
Legal settlement	$ 2,500
Purchase Commitments [Abstract]
Maximum purchase commitment period (in years) | yr	1
Aggregate total of non-cancelable purchase commitments	$ 39,500
Product warranty accrual [Roll Forward]
Accrual balance at beginning of year	2,792	3,501	4,476
Accruals for product warranties	3,025	3,985	5,346
Cost of warranty claims	(3,583)	(4,694)	(6,321)
Accrual balance at end of period	2,234	$ 2,792	$ 3,501	$ 3,501
Operating Leases on Vacated Facilities [Member]
Operating Lease Commitments [Abstract]
Aggregate obligation of vacated facilies	7,000
Restructuring Reserve	1,700
Standby Letters of Credit [Member]
Operating Lease Commitments [Abstract]
Letters of Credit Outstanding, Amount	$ 400
Standby Letters of Credit [Member] | Office Space - Burlington, Massachusetts [Member]
Operating Lease Commitments [Abstract]
Number of five-year renewal options on corporate office space in Burlington, Massachusetts	2
Maximum exposure	$ 2,200
Minimum exposure	$ 1,200