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 loss	$ (72,314)	$ (15,661)	$ (46,248)
Adjustments to reconcile net loss to net cash provided by operating activities:
Amortization of intangibles	14,836	6,502	20,520
Depreciation	18,819	13,241	16,459
Stock-based compensation	13,060	15,582	17,287
Amortization of discount on convertible debt	4,964	216	0
Provision for non-cash warrant	434
Restructuring, asset impairment and (gain) loss on retirement of fixed assets	2,305	641	1,622
Loss on impairment of long-term investment	2,735	2,505	0
Gain on pension curtailment	(1,955)
Deferred income taxes, net	(10,085)	(512)	32,163
Provision for doubtful accounts, returns and discounts	2,589	2,034	1,943
Provision for excess and obsolete inventories	6,871	1,585	2,569
Excess tax benefits from stock-based compensation	0	0	(15)
Other non-cash adjustments, net	408	0	1,108
Changes in operating assets and liabilities, net of effects of acquisition:
Accounts receivable	(2,563)	2,595	(1,035)
Inventories	(4,107)	(5,954)	1,610
Prepaid expenses and other assets	(1,892)	(8,206)	(3,332)
Accounts payable	5,793	4,683	56
Deferred revenues	18,106	(4,541)	11,162
Income taxes payable	(133)	(1,637)	(7,094)
Accrued and other liabilities	2,567	(6,722)	(1,406)
Net cash provided by operating activities	438	6,351	47,369
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(75,669)
Purchases of investments	0	(25,261)	(26,599)
Proceeds from maturities of investments	19,707	30,379	60,811
Proceeds from sales of investments	0	0	13,045
Purchases of property and equipment	(15,107)	(14,356)	(10,065)
Purchases of long-term investments	0	(85)	(9,393)
Restricted cash	591	(1,091)	0
Net cash (used in) provided by investing activities	(70,478)	(10,414)	27,799
Cash flows from financing activities:
Proceeds from convertible debt	0	128,250	0
Payment of convertible debt issuance cost	(582)	(3,527)	0
Proceeds from other debts and capital leases	5,968
Repayment of other debts and capital leases	(8,338)
Proceeds from common stock issued to employees	4,444	9,222	4,742
Payment of tax withholding obligations related to net share settlements of restricted stock units	(1,644)	(3,549)	(3,636)
Payments for repurchases of common stock	0	(72,863)	(93,128)
Excess tax benefits from stock-based compensation	0	0	15
Net cash (used in) provided by financing activities	(152)	57,533	(92,007)
Effect of exchange rate changes on cash and cash equivalents	(363)	(312)	(458)
Net (decrease) increase in cash and cash equivalents	(70,555)	53,158	(17,297)
Cash and cash equivalents at beginning of period	126,190	73,032	90,329
Cash and cash equivalents at end of period	55,635	126,190	73,032
Supplemental disclosures of cash flow information:
Income tax payments (refunds), net	(54)	952	1,926
Interest payments, net	5,275
Supplemental schedule of non-cash investing and financing activities:
Capital expenditures incurred but not yet paid	394	235	854
Debt issuance costs incurred but not yet paid	$ 0	$ 582	$ 0