Marketable Securities (Tables)

3 Months Ended

Apr. 27, 2014

Notes to financial statements [Abstract]

Cash Equivalents and Marketable Securities

	April 27, 2014
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Corporate debt securities	$	2,065,847	$	2,671	$	(692	)	$	2,067,826
Debt securities of United States government agencies	732,145		684		(98		)	732,731
Debt securities issued by United States Treasury	584,036		884		(40		)	584,880
Asset-backed securities	357,216		239		(124		)	357,331
Mortgage-backed securities issued by United States government-sponsored enterprises	199,362		3,874		(795		)	202,441
Money market funds	103,396		—		—			103,396
Total	$	4,042,002	$	8,352	$	(1,749	)	$	4,048,605
Classified as:
Cash equivalents								$	209,953
Marketable securities								3,838,652
Total								$	4,048,605

	January 26, 2014
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Corporate debt securities	$	1,827,788	$	1,857	$	(1,065	)	$	1,828,580
Debt securities of United States government agencies	1,012,740		848		(261		)	1,013,327
Debt securities issued by United States Treasury	495,889		621		(57		)	496,453
Money market funds	307,865		—		—			307,865
Asset-backed securities	258,017		15		(315		)	257,717
Mortgage-backed securities issued by United States government-sponsored enterprises	185,594		3,837		(725		)	188,706
Total	$	4,087,893	$	7,178	$	(2,423	)	$	4,092,648
Classified as:
Cash equivalents								$	572,425
Marketable securities								3,520,223
Total								$	4,092,648

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than 12 months					12 months or greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In thousands)
Corporate debt securities	$	807,941	$	(41	)	$	1,259,885	$	(651	)	$	2,067,826	$	(692	)
Debt securities of United States government agencies	408,621		(9		)	324,110		(89		)	732,731		(98		)
Debt securities issued by United States Treasury	64,259		—			520,621		(40		)	584,880		(40		)
Asset-backed securities	153,635		(30		)	203,696		(94		)	357,331		(124		)
Mortgage-backed securities issued by United States government-sponsored enterprises	—		—			202,441		(795		)	202,441		(795		)
Total	$	1,434,456	$	(80	)	$	2,510,753	$	(1,669	)	$	3,945,209	$	(1,749	)

Schedule of Cash Equivalents and Marketable Securities Available for Sale

	April 27, 2014				January 26, 2014
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In thousands)
Less than 1 year	$	1,536,890	$	1,537,853	$	1,883,132	$	1,883,753
Due in 1 - 5 years	2,379,798		2,383,465		2,114,289		2,117,387
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	125,314		127,287		90,472		91,508
Total	$	4,042,002	$	4,048,605	$	4,087,893	$	4,092,648