CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 10,979	$ 16,175
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,775	6,374
Provision for doubtful accounts	107
Non-cash interest expense	3,160	2,958
Stock-based compensation expense	7,672	4,845
Deferred tax expense	472	(13,062)
Loss on conversion of convertible senior notes	1
Loss on disposal of assets		64
Changes in assets and liabilities:
Accounts receivable	(1,583)	(8,472)
Other receivables	(149)	196
Inventories	(4,805)	699
Prepaid expenses and other current assets	(1,437)	(739)
Other assets	(1,348)	(704)
Accounts payable	3,354	159
Accrued liabilities	(1,070)	(6,089)
Long-term liabilities	87	(171)
Net cash provided by operating activities	27,215	2,233
Cash flows from investing activities:
Acquisition of Spectrum Inc., net of cash received		(112,941)
Purchases of marketable securities		(48)
Redemptions of marketable securities		19,600
Purchases of property, plant and equipment	(8,580)	(3,686)
Net cash used in investing activities	(8,580)	(97,075)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs		129,309
Exercise of stock options	2,374	2,035
Repayment of senior convertible notes	(11)
Payment of contingent consideration		(1,702)
Net cash provided by financing activities	2,363	129,642
Effect of exchange rate changes on cash and cash equivalents	(4,453)	2,633
Net increase in cash, cash equivalents and restricted cash	16,545	37,433
Cash, cash equivalents and restricted cash, beginning of period	173,759	122,233
Cash, cash equivalents and restricted cash, end of period	190,304	159,666
Cash paid during the period for:
Income taxes	3,120	3,555
Interest	1,222	1,222
Non-cash investing and financing activities:
Non-cash effect of adoption of ASU 2016-16	5,609
Payment of contingent consideration in common stock		1,062
Stock tendered for acquisition of Spectrum		$ 247,575
Property, plant and equipment related to lease incentives	$ 2,270