CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2017	May 01, 2016
Cash flows from operating activities:
Net income	$ 507	$ 208
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47	45
Stock-based compensation expense	76	53
Deferred income taxes	22	30
Amortization of debt discount	2	8
Loss on early debt conversions	14	0
Net gain on sale and disposal of long-lived assets and investments	0	(3)
Other	5	(4)
Changes in operating assets and liabilities:
Accounts receivable	(150)	(17)
Inventories	(27)	23
Prepaid expenses and other assets	(2)	(18)
Accounts payable	(133)	32
Accrued and other current liabilities	(87)	(7)
Other long-term liabilities	8	(31)
Net cash provided by operating activities	282	319
Cash flows from investing activities:
Proceeds from sales of marketable securities	649	529
Proceeds from maturities of marketable securities	200	175
Purchases of marketable securities	(36)	(469)
Purchases of property and equipment and intangible assets	(54)	(55)
Other	(5)	(4)
Net cash provided by investing activities	754	176
Cash flows from financing activities:
Payments related to repurchases of common stock	0	(500)
Repayment of convertible notes	(605)	0
Dividends paid	(82)	(62)
Proceeds related to employee stock plans	65	70
Payments related to tax on restricted stock units	(190)	(51)
Other	(1)	(1)
Net cash used in financing activities	(813)	(544)
Change in cash and cash equivalents	223	(49)
Cash and cash equivalents at beginning of period	1,766	596
Cash and cash equivalents at end of period	1,989	547
Other non-cash activity:
Assets acquired by assuming related liabilities	$ 14	$ 11