Long-term debt (Tables)

9 Months Ended

Oct. 26, 2014

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

	October 26,			January 26,
	2014			2014
	(In thousands)
Amount of the equity component	$	125,725		$	125,725
1.00% convertible senior notes due 2018	$	1,500,000		$	1,500,000
Unamortized debt discount (1)	(122,741		)	(143,625		)
Net carrying amount	$	1,377,259		$	1,356,375

(1) As of October 26, 2014, the unamortized debt discount will be amortized over a remaining period of 4.1 years.

The following table presents interest expense for the contractual interest and the accretion of debt discount and issuance costs:

	Three Months Ended				Nine Months Ended
	October 26,		October 27,		October 26,		October 27,
	2014		2013		2014		2013
	(In thousands)
Contractual coupon interest expense	$	3,750	$	—	$	11,250	$	—
Amortization of debt discount	7,010		—		20,884		—
Amortization of debt issuance costs	49		—		146		—
Total interest expense related to Notes	$	10,809	$	—	$	32,280	$	—