Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities
Net income	$ 45,621	$ 52,303
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	22,886	22,628
Amortization of premiums on investments, net of accretion of discounts	5,209	4,523
Stock-based compensation	12,859	12,338
Excess tax benefit from employee stock-based compensation	(3,916)	(919)
Deferred revenue	12	(1,241)
Deferred income tax	(1,632)	(1,930)
Gain on contingent consideration		(6,082)
Loss on disposal of property and equipment	207	143
Changes in assets and liabilities:
Trade and other accounts receivable	4,290	(1,494)
Inventories	(540)	2,998
Prepaid expenses	(4,205)	1,907
Other current assets	44	918
Other long-term assets	(453)	390
Accounts payable	(3,417)	(7,082)
Accrued salaries and employee benefits	(3,999)	(4,336)
Other accrued expenses	342	(1,086)
Income tax payable	11,437	8,530
Other long-term liabilities	769	(684)
Net cash provided by operating activities	85,514	81,824
Investing activities
Proceeds from sales and maturities of marketable securities	223,439	281,958
Purchases of marketable securities	(162,258)	(168,395)
Purchases of property, plant and equipment	(23,245)	(14,567)
Purchases of capitalized software	(2,547)	(1,457)
Purchases of intangible assets, including licenses and manufacturing access fees	(4,424)	(1,865)
Cash paid for investment in Pacific Biosciences		(50,000)
Cash paid for investment in Roka Biosciences	(3,980)
Other	(348)	(1,967)
Net cash provided by investing activities	26,637	43,707
Financing activities
Repurchase and retirement of common stock	(47,972)	(52,299)
Proceeds from issuance of common stock and employee stock purchase plan	40,727	20,062
Repurchase and retirement of restricted stock for payment of taxes	(363)	(43)
Excess tax benefit from employee stock-based compensation	3,916	919
Borrowings, net	8,000
Net cash provided by (used in) financing activities	4,308	(31,361)
Effect of exchange rate changes on cash and cash equivalents	570	(1,864)
Net increase in cash and cash equivalents	117,029	92,306
Cash and cash equivalents at the beginning of period	59,690	82,616
Cash and cash equivalents at the end of period	$ 176,719	$ 174,922