CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 217	$ (1,023)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	993	1,460
Amortization of marketable securities premium	10	18
Impairment charge on equity investee		1,068
Stock-based compensation	643	558
Loss on disposal of equipment		31
Gain from deconsolidation of a subsidiary		(175)
Loss from equity method investments, net	120	561
Changes in operating assets and liabilities:
Accounts receivable	(4,691)	153
Inventories	354	6,279
Prepaid expenses and other current assets	(2,042)	517
Other assets	(1,383)	(766)
Accounts payable	(484)	(5,555)
Accrued liabilities	(1,388)	(5,996)
Other long-term liabilities, including royalties	1,547	7
Net cash used in operating activities	(6,104)	(2,863)
Cash flows from investing activities:
Purchases of property, plant and equipment	(2,139)	(2,909)
Proceeds from sales and maturities of available-for-sale debt securities	720	9,800
Net cash provided by (used in) investing activities	(1,419)	6,891
Cash flows from financing activities:
Proceeds from common stock options exercised	441
Proceeds from sale of previously consolidated subsidiary shares		366
Proceeds from short-term loan	391
Net cash provided by financing activities	832	366
Effect of exchange rate changes on cash and cash equivalents	(140)	140
Net increase (decrease) in cash and cash equivalents	(6,831)	4,534
Cash and cash equivalents at the beginning of the year	26,892	16,526
Cash and cash equivalents at the end of the year	$ 20,061	$ 21,060