Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 61,575	$ 42,707
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	8,706	7,833
Change in fair value of contingent consideration	881
Share-based compensation expense	23,165	16,354
Deferred taxes	19,176	12,900
Marketable securities premium amortization	201	597
Unrealized foreign currency (gain) loss	(4,802)	7,532
Unrealized (gain) loss on forward contracts	(2,746)	2,416
Loss on disposal of property, plant and equipment		63
Changes in operating assets and liabilities, excluding the effect of acquisitions:
Accounts receivable	(35,768)	(24,141)
Inventories	(9,500)	(13,776)
Prepaid expenses and other assets	(5,491)	6,620
Accounts payable and accrued expenses	36,934	6,366
Deferred revenue	10,714	1,483
Net cash provided by operating activities	103,045	66,954
Cash flows from investing activities:
Purchases of marketable securities		(23,647)
Proceeds from maturity or sale of marketable securities	74,100	5,250
Purchases of property, plant and equipment	(9,836)	(5,503)
Purchase of technology rights		(20)
Payments for acquisition of business, net of cash acquired	(105,886)
Increase in restricted cash	(348)
Net cash used in investing activities	(41,970)	(23,920)
Cash flows from financing activities:
Payments on capital leases	(290)	(305)
Excess tax benefit from stock options	1,532	712
Proceeds from revolving credit facility	60,000
Payments on revolving credit facility	(60,000)
Net proceeds from the exercise of stock options	16,546	13,803
Net cash provided by financing activities	17,788	14,210
Effect of exchange rate changes on cash	1,860	(2,312)
Net change in cash and cash equivalents	80,723	54,932
Cash and cash equivalents at beginning of period	267,145	157,172
Cash and cash equivalents at end of period	$ 347,868	$ 212,104