Guarantees (Details) (USD $)	3 Months Ended				6 Months Ended
	Jul. 28, 2013		Jul. 29, 2012		Jul. 28, 2013	Jul. 29, 2012
Estimated product warranty liabilities
Balance at beginning of period (1)	$ 14,833,000	[1]	$ 17,070,000	[1]	$ 14,874,000	$ 18,406,000
Additions	3,482,000		1,678,000		4,900,000	3,357,000
Deductions (2)	(841,000)	[2]	(2,211,000)	[2]	(2,300,000)	(5,226,000)
Balance at end of period	17,474,000		16,537,000		17,474,000	16,537,000
Incremental repair and replacement costs for the weak die/packaging material set	9,100,000		11,600,000		9,600,000	13,200,000
Payments related to warranty accrual			$ 700,000		$ 500,000	$ 1,900,000

[1] Includes $9.1 million and $9.6 million for the three and six months ended July 28, 2013, respectively, and $11.6 million and $13.2 million for the three and six months ended July 29, 2012, respectively, related to warranty accrual associated with incremental repair and replacement costs from a weak die/packaging material set.

[2] $0.5 million for the six months ended July 28, 2013, and $0.7 million and $1.9 million for the three and six months ended July 29, 2012, respectively. No payments were made for the three months ended July 28, 2013.