Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities
Net income	$ 37,198	$ 13,759
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	6,842	4,239
Net loss on disposal of assets	7	334
Stock-based compensation	2,650	1,566
Realized gain on investments		(8)
Deferred taxes	14,576
Excess tax benefits from stock-based compensation	(4,301)
Changes in operating assets and liabilities:
Accounts receivable	(10,609)	(7,606)
Inventories	(5,826)	(1,821)
Other inventory supplies	(5,803)	(3,927)
Prepaid expenses and other current assets	(2,188)	(215)
Accounts payable	(2,386)	2,500
Accrued payroll	(434)	858
Corporate income and franchise taxes	(154)	(20)
Advanced payments	(838)	586
Accrued and other current liabilities	2,064	508
Net cash provided by operating activities	30,798	10,753
Cash flows from investing activities
Purchases of property and equipment	(40,656)	(34,896)
Proceeds from disposal of assets		42
Purchases of investments	(191)	(55,201)
Proceeds from sale of investments	12,528	24,800
Net cash (used in) investing activities	(28,319)	(65,255)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs of $4,130		61,723
Proceeds from exercise of options	741	1,378
Restricted cash	19	(525)
Purchase of treasury stock	(5,482)
Excess tax benefits from stock-based compensation	4,301
Net cash (used in) provided by financing activities	(421)	62,576
Net effect of currency translation	226	28
Net increase in cash and cash equivalents	2,284	8,102
Cash and cash equivalents, beginning of period	16,073	3,860
Cash and cash equivalents, end of period	18,357	11,962
Supplemental disclosures of cash flow information Cash paid for income taxes	6,050
Supplemental disclosures of non-cash transactions Unrealized loss on investments	$ 81	$ 1

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7

-Footnote 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016