Condensed 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	$ 22,417	$ 16,583
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,245	3,162
Stock-based compensation	6,964	1,134
Net loss on disposals and impairments of assets	4	78
Excess tax benefits from stock-based compensation	(2,372)	(296)
Deferred income taxes	(2,610)	1,442
Changes in operating assets and liabilities:
Accounts receivable	1,390	1,159
Inventories	(33)	1,114
Income taxes	10,388	6,531
Prepaid expenses and other assets	186	(2,533)
Accounts payable	6,591	4,181
Customer prepayments	6,348	2,580
Accrued compensation and benefits	(12,449)	(6,681)
Other taxes and withholding	1,160	1,305
Warranty liabilities	569	(119)
Other accruals and liabilities	1,720	2,583
Net cash provided by operating activities	44,518	32,223
Cash flows from investing activities:
Purchases of property and equipment	(9,281)	(2,744)
Proceeds from sales of property and equipment	9	0
Increase in restricted cash	0	(2,650)
Net cash used in investing activities	(9,272)	(5,394)
Cash flows from financing activities:
Net decrease in short-term borrowings	(3,371)	(1,119)
Excess tax benefits from stock-based compensation	2,372	296
Proceeds from issuance of common stock	1,655	143
Repurchases of common stock	(1,214)	(283)
Net cash used in financing activities	(558)	(963)
Net increase in cash and cash equivalents	34,688	25,866
Cash and cash equivalents, at beginning of period	116,255	76,016
Cash and cash equivalents, at end of period	$ 150,943	$ 101,882

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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).