CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Beginning Balance, Stockholders' Equity at Jan. 25, 2009	$ 2,394,652,000	$ 629,000	$ 1,889,257,000	$ (1,463,268,000)	$ 3,865,000	$ 1,964,169,000
Beginning Common Stock, Shares, Outstanding at Jan. 25, 2009		538,460,766
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in Unrealized Gain (Loss), Net of Tax	9,417,000				9,417,000
Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	(1,110,000)				(1,110,000)
Net income (loss)	(67,987,000)		0	0		(67,987,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(59,680,000)
Stock Issued During Period, Shares, Employee Stock Ownership Plan		23,005,124
Stock Issued During Period, Value, Employee Stock Ownership Plan	138,029,000	24,000	138,005,000
Shares Paid for Tax Withholding for Share Based Compensation	(39)
Tax benefit from stock options	29,891,000		29,891,000
Allocated Share-based Compensation Expense	104,588,000		104,588,000
Payments related to stock option purchase	(78,075,000)		(78,075,000)
Stock-based compensation expense related to stock option purchase	135,735,000		135,735,000
Ending Balance, Stockholders' Equity at Jan. 31, 2010	2,665,140,000	653,000	2,219,401,000	(1,463,268,000)	12,172,000	1,896,182,000
Ending Common Stock, Shares, Outstanding at Jan. 31, 2010		561,465,851
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in Unrealized Gain (Loss), Net of Tax	(918,000)				(918,000)
Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	(982,000)				(982,000)
Net income (loss)	253,146,000					253,146,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	251,246,000
Stock Issued During Period, Shares, Employee Stock Ownership Plan		28,207,000
Stock Issued During Period, Value, Employee Stock Ownership Plan	193,405,000	24,000	193,381,000
Shares Paid for Tax Withholding for Share Based Compensation		(1,117,179)
Adjustments Related to Tax Withholding for Share-based Compensation	(16,124,000)			(16,124,000)
Tax benefit from stock options	(14,201,000)		(14,201,000)
Allocated Share-based Compensation Expense	101,996,000		101,996,000
Payments related to stock option purchase	0
Stock-based compensation expense related to stock option purchase	0
Ending Balance, Stockholders' Equity at Jan. 30, 2011	3,181,462,000	677,000	2,500,577,000	(1,479,392,000)	10,272,000	2,149,328,000
Ending Common Stock, Shares, Outstanding at Jan. 30, 2011	588,555,701	588,555,701
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in Unrealized Gain (Loss), Net of Tax	755,000				755,000
Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	(413,000)				(413,000)
Net income (loss)	581,090,000					581,090,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	581,432,000
Stock Issued During Period, Shares, Employee Stock Ownership Plan		24,753,362
Stock Issued During Period, Value, Employee Stock Ownership Plan	213,369,000	23,000	213,346,000	0
Shares Paid for Tax Withholding for Share Based Compensation		(1,117,651)
Adjustments Related to Tax Withholding for Share-based Compensation	(17,512,000)			(17,512,000)
Tax benefit from stock options	50,475,000		50,475,000
Allocated Share-based Compensation Expense	136,498,000		136,498,000
Payments related to stock option purchase	0
Stock-based compensation expense related to stock option purchase	0
Ending Balance, Stockholders' Equity at Jan. 29, 2012	$ 4,145,724,000	$ 700,000	$ 2,900,896,000	$ (1,496,904,000)	$ 10,614,000	$ 2,730,418,000
Ending Common Stock, Shares, Outstanding at Jan. 29, 2012	612,191,412	612,191,412