Segment Information Revenue and Long-lived assets by region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 26, 2014	Oct. 27, 2013	Jul. 28, 2013	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 26, 2014	Jan. 27, 2013	Jan. 29, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,144,218	$ 1,053,967	$ 977,238	$ 954,739	$ 1,106,902	$ 1,204,110	$ 1,044,270	$ 924,877	$ 4,130,162	$ 4,280,159	$ 3,997,930
Long-Lived Assets	686,992				683,624				686,992	683,624
CHINA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									793,790	780,493	941,811
Long-Lived Assets	29,313				34,644				29,313	34,644
TAIWAN
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,321,503	1,356,838	1,137,175
Long-Lived Assets	51,993				45,868				51,993	45,868
Other Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									675,339	783,573	730,975
Long-Lived Assets	1,092				941				1,092	941
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									295,160	263,488	296,591
Long-Lived Assets	50,677				28,190				50,677	28,190
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									726,830	799,430	596,264
Long-Lived Assets	522,461				542,669				522,461	542,669
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									317,540	296,337	295,114
INDIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 31,456				$ 31,312				$ 31,456	$ 31,312