Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 28, 2012	Jan. 29, 2011	Jan. 30, 2010
Cash flows from operating activities:
Net income (loss)	$ (168,045)	$ 9,147	$ 2,455
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	28,952	27,680	13,169
Stock-based compensation	12,025	12,577	8,793
Provision for excess and obsolete inventory	8,955	488	259
Provision for sales returns, discounts and doubtful accounts	54	260	485
Deferred income taxes	(10,221)	(4,806)	(64)
Loss on disposal of software, equipment and leasehold improvements	173	449	212
Impairment of investment		5,203
Tax benefit from employee stock option plan	1,595	2,320	88
Excess tax benefit from stock-based compensation	(1,938)	(2,320)	(613)
Accretion of contributed leasehold improvements	(260)	(176)	(171)
Impairment (adjustment) of goodwill and intangible assets	111,278		(217)
Changes in operating assets and liabilities:
Accounts receivable	10,114	4,517	(3,183)
Inventories	6,964	(20,015)	27,129
Prepaid expenses and other current assets	(443)	(697)	1,549
Other non-current assets	156	84	(373)
Accounts payable	(7,968)	4,705	2,978
Accrued liabilities	(4,114)	1,028	(1,596)
Other long-term liabilities	577	1,428	1,031
Net cash provided by (used in) by operating activities	(12,146)	41,872	51,931
Cash flows from investing activities:
Restricted cash	(153)	(116)	(500)
Purchases of marketable securities	(88,072)	(130,530)	(55,305)
Sales and maturities of marketable securities	88,515	90,320	92,351
Purchases of software, equipment and leasehold improvements	(14,239)	(14,653)	(7,469)
Net cash paid in connection with acquisitions	(5,000)		(89,110)
Purchases of long-term investments	(2,142)	(2,300)	(1,524)
Repayment of note receivable	150
Purchase of notes receivable	(2,500)	(1,150)
Purchase of convertible note receivable			(3,000)
Net cash used in investing activities	(23,441)	(58,429)	(64,557)
Cash flows from financing activities:
Net proceeds from exercise of employee stock options and stock purchase rights	5,377	5,243	2,807
Excess tax benefit on stock-based compensation	1,938	2,320	613
Net cash provided by financing activities	7,315	7,563	3,420
Effect of foreign exchange rate changes on cash and cash equivalents	(177)	(221)	308
Decrease in cash and cash equivalents	(28,449)	(9,215)	(8,898)
Cash and cash equivalents at beginning of period	72,732	81,947	90,845
Cash and cash equivalents at end of period	44,283	72,732	81,947
Supplemental disclosure of cash flow information:
Cash paid for interest		148	77
Cash paid for income taxes	1,330	1,623	619
Issuance of common stock in connection with acquisition			$ 48,513