Condensed 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)	$ (2,787)	$ (10,699)	$ 11,862
Reconciliation to net cash provided by operating activities:
Impairment of long-lived assets	206	439	126
Loss on disposal of property, plant, and equipment	104	46	91
Depreciation of property, plant, and equipment	11,314	12,528	11,171
Amortization of product rights, trademarks, and patents	1,938	1,920	1,907
Imputed interest accretion	110	163
Employee share-based compensation expense	11,684	8,334	6,089
Non-employee share-based compensation expense	1,131	946	946
Reserve for income tax liabilities	(1)	499	(167)
Changes in deferred taxes	(7,880)	(8,743)	2,248
Changes in operating assets and liabilities:
Accounts receivable, net	(11,012)	1,210	11,824
Inventories, net	9,775	6,565	(18,538)
Income tax refund and deposits	21	1,873	(576)
Prepaid expenses and other assets	(699)	(88)	29
Income taxes payable	(92)	559	(173)
Accounts payable and accrued liabilities	(3,131)	5,500	4,203
Net cash provided by operating activities	10,681	21,052	31,042
Cash Flows From Investing Activities:
Acquisition of business		(18,352)
Purchases of property, plant, and equipment	(14,418)	(18,671)	(17,642)
Capitalized labor, overhead, and interest on self-constructed assets	(1,629)	(1,828)	(660)
Proceeds from the sale of property, plant and equipment	51
Sales of short-term investments, net			513
Decrease (increase) in restricted cash	210	(170)	50
Deposits and other assets, net	(1,139)	(752)	(559)
Net cash used in investing activities	(16,925)	(39,773)	(18,298)
Cash Flows From Financing Activities:
Net proceeds from issuance of common stock	1,320	38,018
Repurchase of common stock	(621)	(389)	(199)
Excess tax benefit (reduction) related to share-based compensation	107	(1,109)	(647)
Net proceeds from equity plans	13,502	571	55
Cost related to public offering		(1,920)
Deferred offering cost			(1,427)
Payments on treasury stock	(9,865)	(345)
Proceeds from borrowing under lines of credit		25,000	66,000
Repayments under lines of credit		(40,000)	(71,000)
Proceeds from issuance of long-term debt	6,785	26,505
Principal payments on long-term debt	(8,991)	(8,216)	(2,152)
Principal payments on short-term debt		(5,998)
Net cash provided by (used in) financing activities	2,237	32,117	(9,370)
Effect of exchange rate changes on cash	2,253	845
Net increase (decrease) in cash and cash equivalents	(1,754)	14,241	3,374
Cash and cash equivalents at beginning of period	67,828	53,587	50,213
Cash and cash equivalents at end of period	66,074	67,828	53,587
Noncash Investing and Financing Activities:
Equipment acquired under capital leases	150	78	1,323
Supplemental Disclosures of Cash Flow Information:
Interest paid	1,941	2,607	1,100
Income taxes paid	$ 146	$ 436	$ 4,158