CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows From Operating Activities:
Net income (loss)	$ 2,096	$ 44,766
Reconciliation to net cash provided by operating activities:
Loss (gain) on impairment and disposal of assets	30	850
Depreciation of property, plant, and equipment	9,531	8,311
Amortization of product rights, trademarks, and patents	509	526
Operating lease right-of-use asset amortization	1,700	1,390
Share-based compensation	11,795	8,706
Changes in deferred taxes, net	1,638	9,872
Changes in operating assets and liabilities:
Accounts receivable, net	(4,454)	1,700
Inventories	5,760	(30,012)
Prepaid expenses and other assets	541	(1,221)
Income tax refunds, deposits, and payables, net	(78)	1,784
Operating lease liabilities	(1,565)	(1,297)
Accounts payable and accrued liabilities	4,063	2,738
Net cash provided by operating activities	31,566	48,113
Cash Flows From Investing Activities:
Purchases and construction of property, plant, and equipment	(18,895)	(24,467)
Purchase of short-term investments	669
Payment of deposits and other assets	(562)	(86)
Net cash used in investing activities	(18,788)	(24,553)
Cash Flows From Financing Activities:
Proceeds from the private placement of ANP		18,298
Proceeds from equity plans, net of withholding tax payments	18,210
Proceeds from equity plans, net of withholding tax payments		(157)
Purchase of treasury stock	(16,706)	(4,088)
Proceeds from borrowing under lines of credit	705
Repayments under lines of credit		(347)
Proceeds from issuance of long-term debt	3,067
Principal payments on long-term debt	(4,269)	(3,219)
Net cash provided by (used in) financing activities	1,007	10,487
Effect of exchange rate changes on cash	(82)	(11)
Net increase (decrease) in cash, cash equivalents and restricted cash	13,703	34,036
Cash, cash equivalents, and restricted cash at beginning of period	75,550	88,202
Cash, cash equivalents, and restricted cash at end of period	89,253	122,238
Noncash Investing and Financing Activities:
Capital expenditure included in accounts payable	9,662	6,631
Operating lease right-of-use assets		7,671
Equipment acquired under finance leases	61	61
Supplemental Disclosures of Cash Flow Information:
Interest paid, net of capitalized interest	1,119	1,277
Income taxes paid	$ 662	$ 1,147