Goodwill and Intangible Assets - Changes in Carrying Amounts of Goodwill (Details) $ in Thousands	9 Months Ended
	Oct. 25, 2015 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 280,319
Additions	49,384
Ending balance	329,703
Signal Integrity [Member]
Goodwill [Roll Forward]
Beginning balance	261,891
Additions	0
Ending balance	261,891
Power and High Reliability [Member]
Goodwill [Roll Forward]
Beginning balance	0
Additions	49,384
Ending balance	49,384
Wireless, Sensing and Timing [Member]
Goodwill [Roll Forward]
Beginning balance	18,428
Additions	0
Ending balance	$ 18,428