Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 29, 2013		Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 14,548		$ 21,371
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	2,651		2,206
Amortization of intangibles and other	927		270
Amortization of security discount (premium)	397		(166)
Stock-based compensation	6,679		5,025
Deferred income taxes	0		5
Changes in operating assets and liabilities:
Accounts receivable	(3,442)		(7,498)
Inventories	(9,219)		(5,771)
Prepaid expenses and other current assets	(908)		1,424
Other assets	158		(654)
Accounts payable	(1,191)		5,380
Deferred product and services income	(9,285)		10,342
Other current liabilities	(2,898)		(5,171)
Other liabilities	518		3,673
Net cash provided by (used in) operating activities	(1,065)		30,436
Cash flows from investing activities:
Capital expenditures	(5,188)		(2,905)
Purchase of intangible assets	(5,000)		(8,000)
Purchase of investments in securities	(128,146)		(171,247)
Proceeds from maturities of investments	97,792		151,633
Net cash used in investing activities	(40,542)		(30,519)
Cash flows from financing activities:
Proceeds from notes payable	2,000		2,000
Repayment of notes payable	(2,000)		(2,000)
Proceeds from issuance of common stock for stock option exercises	12,278		5,853
Tax payment for issuance of common stock from release of restricted stock units	(3,360)		(4,278)
Net cash provided by financing activities	8,918		1,575
Net increase (decrease) in cash and cash equivalents	(32,689)		1,492
Cash and cash equivalents at beginning of period	96,968	[1]	58,780
Cash and cash equivalents at end of period	$ 64,279		$ 60,272

[1] The balance sheet as of December 31, 2012 has been derived from the audited financial statements at that date.