Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities
Net (loss) income	$ (30,351)	$ (5,538)	$ 38,059
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities
Depreciation and amortization	12,660	12,027	9,724
Net loss on disposal of assets	550	19	84
Stock-based compensation	1,375	1,801	2,297
Stock issued to Board of Directors	220	162	162
Realized gain on investments		(8)
Deferred taxes	(5,166)	(6,324)	13,447
Excess tax benefits from stock-based compensation	114	(160)	(1,404)
Changes in operating assets and liabilities:
Accounts receivable	9,098	19,975	(13,968)
Inventories	12,979	(24,258)	(11,948)
Other inventory supplies	2,976	1,948	(9,929)
Prepaid expenses and other assets	1,571	1,981	(3,993)
Accounts payable	(4,472)	(4,004)	3,683
Accrued payroll	(510)	(581)	(951)
Corporate income and franchise taxes	(25)	(391)	212
Accrued real estate taxes	39	22	49
Advance payments	(364)	763	(1,094)
Accrued and other current liabilities	(282)	(172)	182
Net cash provided by (used in) operating activities	412	(2,738)	24,612
Cash flows from investing activities
Purchases of property and equipment	(8,721)	(10,975)	(48,228)
Proceeds from disposal of assets	141	10
Purchase of investments	(2,040)	(5,281)	(9,439)
Proceeds from sale of investments	11,390	34,300	25,000
Net cash provided by (used in) investing activities	770	18,054	(32,667)
Cash flows from financing activities
Proceeds from exercise of options	140	72	742
Restricted cash	6	18	344
Purchase of treasury stock			(6,487)
Excess tax benefits from stock-based compensation	(114)	160	1,404
Net cash provided by (used in) financing activities	32	250	(3,997)
Net effect of currency translation	284	(283)	269
Net increase (decrease) in cash and cash equivalents	1,498	15,283	(11,783)
Cash and cash equivalents, beginning of year	19,573	4,290	16,073
Cash and cash equivalents, end of year	21,071	19,573	4,290
Supplemental disclosure of cash flow information
Cash paid for income taxes			6,050
Cash paid for interest	$ 87