ACQUISITION OF NET (Details) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 28, 2012	Jun. 29, 2012	Jun. 29, 2012	Sep. 28, 2012	Sep. 28, 2012 NET	Sep. 30, 2011 NET	Sep. 28, 2012 NET	Sep. 30, 2011 NET	Aug. 24, 2012 NET	Sep. 28, 2012 NET Professional and services fees	Sep. 28, 2012 NET Professional and services fees	Sep. 28, 2012 NET Change of control agreements	Sep. 28, 2012 NET Change of control agreements	Sep. 28, 2012 NET Developed technology	Sep. 28, 2012 NET Customer relationships	Sep. 28, 2012 NET Order backlog	Sep. 28, 2012 NET Internal use software
Acquisition Of Net
Cash consideration									$ 41,500,000
Cash consideration per share of the acquired entity (in dollars per share)									$ 1.35
Revenue					7,200,000		7,200,000
Net loss					2,000,000		2,000,000
Period over which goodwill will be deductible for tax purpose							P15Y
Fair value of consideration transferred:
Cash, net of cash acquired				35,508,000			35,508,000
Fair value of equity awards assumed	892,000			892,000	892,000		892,000
Fair value of total consideration					36,400,000		36,400,000
Allocation of the purchase consideration:
Marketable securities					5,359,000		5,359,000
Deferred income taxes					804,000		804,000
Other current assets					12,095,000		12,095,000
Property and equipment					4,694,000		4,694,000
Noncurrent investments					10,167,000		10,167,000
Intangible assets	16,810,000			16,810,000										9,080,000	6,140,000	860,000	730,000
Goodwill					29,501,000		29,501,000
Other non-current assets					1,843,000		1,843,000
Current liabilities					(9,993,000)		(9,993,000)
Debt					(34,208,000)		(34,208,000)
Other long-term liabilities					(672,000)		(672,000)
Unaudited pro forma results of operations
Revenue					63,358,000	82,484,000	207,847,000	224,789,000
Loss per share					(15,263,000)	(6,777,000)	(48,861,000)	(51,919,000)
Loss per share (in dollars per share)					$ (0.05)	$ (0.02)	$ (0.17)	$ (0.19)
Acquisition-Related Costs
Acquisition-related costs	$ 4,090,000	$ 967,000	$ 967,000	$ 5,057,000						$ 2,048,000	$ 3,015,000	$ 2,042,000	$ 2,042,000