Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2012	Apr. 01, 2011
Cash flow from operating activities:
Net income	$ 50,072	$ 38,872
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	5,562	4,603
Amortization expense	28,797	16,065
Provision for doubtful accounts	587	359
Deferred income taxes	146	(1,393)
Stock-based compensation	7,789	6,798
Income from equity method investments, net	(6,192)	(2,763)
Excess tax benefit for stock-based compensation	(7,580)	(8,357)
Provision for excess and obsolete inventories	3,111	2,489
Other non-cash items	(977)	577
Add decrease (increase) in assets:
Accounts receivable	(46,425)	(40,624)
Other receivables	2,211	5,776
Inventories	5,928	(8,717)
Other current and non-current assets	(7,972)	4,927
Add increase (decrease) in liabilities:
Accounts payable	4,205	16,377
Accrued compensation and benefits	(1,895)	(10,241)
Deferred revenue	29,569	(1,219)
Accrued warranty expense	(728)	(40)
Other current and non-current liabilities	1,450	4,438
Net cash provided by operating activities	67,658	27,927
Cash flow from investing activities:
Acquisitions of businesses, net of cash acquired	(101,392)	(38,979)
Acquisitions of property and equipment	(7,644)	(4,036)
Acquisitions of intangible assets	(755)	(250)
Other	251	44
Net cash used in investing activities	(109,540)	(43,221)
Cash flow from financing activities:
Issuances of common stock, net	26,682	27,785
Excess tax benefit for stock-based compensation	7,580	8,357
Proceeds from long-term debt and revolving credit lines	181,500
Payments on long-term debt and revolving credit lines	(122,850)	(672)
Net cash provided by financing activities	92,912	35,470
Effect of exchange rate changes on cash and cash equivalents	3,495	3,378
Net increase in cash and cash equivalents	54,525	23,554
Cash and cash equivalents, beginning of period	154,621	220,788
Cash and cash equivalents, end of period	$ 209,146	$ 244,342