Commitments, Contingencies and Legal Matters (Details) (USD $)	1 Months Ended	6 Months Ended
	Feb. 28, 2009	Jul. 01, 2012	Dec. 31, 2011
Summary of changes in product warranties
Balance as of December 31, 2011		$ 6,334,000
Accruals for warranties issued during the period		868,000
Adjustments to pre-existing accruals (including changes in estimates)		(470,000)
Warranty liabilities assumed in Sand Force acquisition		426,000
Settlements made during the period (in cash or in kind)		(1,059,000)
Balance as of July 1, 2012		6,099,000
Commitments, Contingencies and Legal Matters (Textual) [Abstract]
Total purchase commitments due through 2016		446,700,000
Company's percentage of take-or-pay agreement with SMP		51.00%
Terms in which take-or-pay agreement may be terminated by either party		Upon two years written notice
Jury award to GE for patent infringement	7,600,000
Outstanding obligation related to standby letters of credit		$ 4,100,000	$ 3,500,000
Period of renewal for standby letter of credit		Annually