Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net income (loss)	$ (5,538)	$ 38,059	$ 29,111
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities
Depreciation and amortization	12,027	9,724	6,066
Loss on disposal of assets	19	84	234
Stock-based compensation	1,801	2,297	2,252
Stock issued to Board of Directors	162	162
Realized gain on investments	(8)		(8)
Deferred taxes	(6,324)	13,447
Excess tax benefits from stock-based compensation	(160)	(1,404)
Changes in operating assets and liabilities:
Accounts receivable	19,975	(13,968)	(13,709)
Inventories	(24,258)	(11,948)	(4,464)
Other inventory supplies	1,948	(9,929)	(5,646)
Prepaid expenses and other assets	1,981	(3,993)	(548)
Accounts payable	(4,004)	3,683	7,129
Accrued payroll	(581)	(951)	2,020
Corporate income and franchise taxes	(391)	212	236
Advance payments	763	(1,094)	1,076
Accrued and other current liabilities	(150)	231	310
Net cash (used in) provided by operating activities	(2,738)	24,612	24,059
Cash flows from investing activities
Purchases of property and equipment	(10,975)	(48,228)	(49,429)
Proceeds from disposal of assets	10		143
Purchase of investments	(5,281)	(9,439)	(55,416)
Proceeds from sale of investments	34,300	25,000	30,000
Net cash provided by (used in) investing activities	18,054	(32,667)	(74,702)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs of 4,130			61,720
Proceeds from exercise of options	72	742	1,640
Restricted cash	18	344	(525)
Purchase of treasury stock		(6,487)
Excess tax benefits from stock-based compensation	160	1,404
Net cash provided by (used in) financing activities	250	(3,997)	62,835
Net effect of currency translation	(283)	269	21
Net increase (decrease) in cash and cash equivalents	15,283	(11,783)	12,213
Cash and cash equivalents, beginning of year	4,290	16,073	3,860
Cash and cash equivalents, end of year	19,573	4,290	16,073
Supplemental disclosure of cash flow information
Cash paid for income taxes		$ 6,050