Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income (loss)	$ 15,988	$ (562)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	14,413	15,758
Deferred taxes	(247)	(2,369)
Provision for bad debts and sales-related allowances	1,597	93
Tax expense from employee stock plans	1,320
Excess tax benefit from stock-based compensation	(1,872)	(404)
Provision for inventory obsolescence	6,055	5,911
Stock-based compensation	17,563	12,138
Asset impairment and restructuring	55	685
Gain on sale of minority investment in a privately-held company	(2,866)
Other non-cash adjustments	833	375
Changes in operating assets and liabilities	(9,994)	(12,729)
Net cash provided by operating activities	42,845	18,896
Cash flows from investing activities:
Purchases of short-term investments	(75,178)	(74,171)
Proceeds from sales and maturities of short-term investments	71,896	73,879
Purchases, net of proceeds from sales, of property and equipment	(7,687)	(2,847)
Businesses purchased, net of cash acquired	(28,966)	(16,448)
Proceeds from sale of minority investment in a privately-held company	2,866
Proceeds from collection of notes receivable from acquired business	713
Net cash used for investing activities	(36,356)	(19,587)
Cash flows from financing activities:
Proceeds from issuance of common stock	8,088	5,879
Purchases of treasury stock and net settlement of restricted stock, including direct transaction costs	(45,055)	(2,948)
Repayment of acquired business debt	(210)
Excess tax benefit from stock-based compensation	1,872	404
Net cash provided by (used for) financing activities	(35,305)	3,335
Effect of foreign exchange rate changes on cash and cash equivalents	(23)	159
Increase (decrease) in cash and cash equivalents	(28,839)	2,803
Cash and cash equivalents at beginning of year	126,363	106,067
Cash and cash equivalents at end of period	$ 97,524	$ 108,870