Long-term debt (Tables)

12 Months Ended

Jan. 25, 2015

Debt Disclosure [Abstract]

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

	January 25, 2015			January 26, 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)	(115,658		)	(143,625		)
Net carrying amount	$	1,384,342		$	1,356,375

(1) As of January 25, 2015, the remaining period over which the unamortized debt discount will be amortized is 3.9 years.

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

	Year Ended
	January 25, 2015		January 26, 2014
	(In thousands)
Contractual coupon interest expense	$	15,000	$	2,500
Amortization of debt discount	27,967		4,600
Amortization of debt issuance costs	195		34
Total interest expense related to Notes	$	43,162	$	7,134