CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 10,113	$ (3,834)	$ (16,327)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	21,838	30,677	38,988
Amortization of inventory step-up in fair value	0	4,666	14,876
Excess tax benefits for share-based compensation	167	0	60
Share-based compensation	14,985	12,411	7,727
Deferred tax assets	(1,209)	(2,078)	(167)
Gain on sale of product line	0	0	(9,295)
Gain on sales of securities	(1,383)	(2,532)	218
Other non-cash transactions	1,380	1,132	5,205
Changes in operating assets and liabilities:
Accounts receivable, net	(11,984)	2,824	2,347
Inventories	(1,058)	603	2,455
Prepaid expenses and other assets	1,490	(460)	(9)
Accounts payable and accrued liabilities	2,410	8,750	(816)
Deferred revenue	(1,086)	(9,859)	9,596
Other long-term liabilities	871	1,183	(1,274)
Net cash provided by operating activities	36,534	43,483	53,584
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short-term investments	(50,000)	0	0
Acquisition of businesses, net of cash acquired	(14,000)	0	0
Proceeds from sales of available-for-sale securities	0	0	9,364
Proceeds from sale of property and equipment	0	130	0
Proceeds from sale of product line	0	0	11,832
Capital expenditures	(10,455)	(7,891)	(4,808)
Capital distribution from non-marketable investments	1,822	3,133	0
Purchase of technology rights	(533)	(43)	(736)
Net cash provided by (used in) investing activities	(73,166)	(4,671)	15,652
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock, net	50,429	1,207	825
Proceeds from term loan and revolver	20,083	0	48,000
Payments of term loan	(23,950)	(16,500)	(81,826)
Debt issuance costs	(249)	0	(1,080)
Excess tax benefits for share-based compensation	(167)	0	0
Repurchase of 3.50% senior convertible notes	0	0	(3,855)
Net cash (used in) provided by financing activities	46,146	(15,293)	(37,936)
Effect of exchange rate changes on cash and cash equivalents	(670)	(724)	157
Net increase in cash and cash equivalents	8,844	22,795	31,457
Cash and cash equivalents at beginning of period	79,923	57,128	25,671
Cash and cash equivalents at end of period	88,767	79,923	57,128
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	4,812	5,434	12,456
Cash paid for income taxes, net of refunds	$ 1,881	$ 1,563	$ 2,222