Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Apr. 02, 2011
Cash flows from operating activities:
Net income	$ 30,164	$ 61,634
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	5,959	5,932
Equity-based compensation	3,800	4,488
Excess tax benefit from equity-based compensation	(66)	(645)
Loss on sale of property and equipment	83	9
Gain on sale of business	0	(67,213)
Deferred income taxes	(391)	2,540
Changes in assets and liabilities:
Accounts receivable, net	(1,862)	12,563
Inventories, net	7,169	(7,136)
Other assets	9,395	(1,690)
Accounts payable	(3,378)	(7,150)
Accrued liabilities	(16,881)	(17,120)
Deferred revenue	1,151	(15,749)
Income taxes	6,135	27,732
Other operating activities	(4,725)	(3,364)
Net cash provided by (used in) operating activities	36,553	(5,169)
Cash flows from investing activities:
Purchases of property and equipment	(7,654)	(3,922)
Proceeds from the sale of business	13,790	164,008
Purchases of investments and marketable securities	(132,390)	(382,410)
Maturities of investments and marketable securities	81,189	209,509
Proceeds from sales of investments and marketable securities	21,748	88,304
Net cash provided by (used in) investing activities	(23,317)	75,489
Cash flows from financing activities:
Purchase of treasury stock	(9,775)	(41,567)
Proceeds from exercise of stock options and stock purchase plan purchases	1,998	2,757
Excess tax benefit from equity-based compensation	66	645
Net cash used in financing activities	(7,711)	(38,165)
Effect of exchange rate changes on cash	0	336
Net increase in cash and cash equivalents	5,525	32,491
Cash balance of discontinued operations at beginning of period	0	1,301
Less: Cash balance of discontinued operations at end of period	0	282
Cash and cash equivalents at beginning of period	36,418	46,175
Cash and cash equivalents at end of period	41,943	79,685
Supplemental disclosures of cash flow information:
Income taxes paid	$ 7,956	$ 8,958

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).