CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 6,820	$ 211,388	$ 26,201
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	21,013	15,096	14,730
Depreciation	12,965	12,379	13,625
Amortization of intangible assets	37,138	25,074	26,618
Non-cash interest expense and amortization of convertible debt issuance costs	6,749	6,372	14,763
Impairment of in-process research and development intangible asset	18,300	0	0
Change in contingent consideration liability	(6,845)	0	0
Impairment of investment in non-marketable equity security	0	0	600
Deferred tax (benefit) provision	(7,116)	(172,706)	2,310
Excess Tax Benefit from Share-based Compensation, Operating Activities	(1,196)	(747)	(481)
Non-cash restructuring	0	583	0
Gain from sale of intellectual property and property, plant and equipment, net	0	(3,670)	(3,529)
Effect of Exchange Rate on assumed cash liability from acquisition	(1,558)	0	0
Change in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	5,797	(10,407)	(3,750)
Prepaids and other assets	(6,205)	(1,042)	476
Inventories	1,748	(3,412)	(2,907)
Accounts payable	2,373	(2,621)	2,006
Accrued salaries and benefits and other accrued liabilities	(4,758)	(2,952)	(17,862)
Deferred revenue	7,313	3,107	3,667
Net cash provided by operating activities	92,538	76,442	76,467
Cash flows from investing activities:
Purchases of property, plant and equipment	(8,556)	(6,132)	(7,204)
Purchases of marketable securities	(54,869)	(157,811)	(240,281)
Maturities of marketable securities	110,081	112,721	118,735
Proceeds from sale of marketable securities	50,546	48,380	24,986
Proceeds from sale of intellectual property and property, plant and equipment, net	113	3,933	5,859
Acquisition of businesses, net of cash acquired	202,523	0	0
Net cash provided by (used in) investing activities	(105,208)	1,091	(97,905)
Cash flows from financing activities:
Proceeds received from issuance of common stock under employee stock plans	15,436	13,783	11,079
Payments under installment payment arrangement	0	(1,717)	(1,773)
Principal payments against financing lease obligation	(661)	(478)	(322)
Payment of additional purchase consideration from acquisition	10,206	0	0
Repurchase and retirement of common stock, including prepayment under accelerated share repurchase program	0	100,113	0
Incremental tax benefits from stock-based compensation	1,196	747	481
Repayment of senior convertible notes	0	0	(172,500)
Net cash provided by (used in) financing activities	5,765	(87,778)	(163,035)
Effect of exchange rate changes on cash and cash equivalents	(1,565)	(117)	(97)
Net decrease in cash and cash equivalents	(8,470)	(10,362)	(184,570)
Cash and cash equivalents at beginning of year	143,764	154,126	338,696
Cash and cash equivalents at end of year	135,294	143,764	154,126
Cash paid during the period for:
Interest	1,553	1,553	5,861
Income taxes, net of refunds	26,787	21,679	20,691
Non-cash investing and financing activities:
Re-measurement of investment upon initial public offering	0	1,264	0
Property, plant and equipment received and accrued in accounts payable and other accrued liabilities	$ 576	$ 240	$ 548