Guarantees (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 27, 2014	Jul. 28, 2013	Jul. 27, 2014	Jul. 28, 2013
Estimated product warranty liabilities
Balance at beginning of period	$ 8,250	$ 14,833	$ 7,571	$ 14,874
Additions	1,155	3,482	3,189	4,900
Deductions	(1,203)	(841)	(2,558)	(2,300)
Balance at end of period	$ 8,202	$ 17,474	$ 8,202	$ 17,474