Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements of Stockholders' Equity
Translation adjustment, tax (in dollars)	$ 23	$ (1)
Cash dividends declared on common stock, per share	$ 0.125	$ 0.125
Common stock issued, per share	$ 33.71	$ 30.91

Tax effect of the adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity that is attributable to the parent entity.

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

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-Name Accounting Standards Codification

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

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-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

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

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-Name Accounting Research Bulletin (ARB)

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 810

-SubTopic 10

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6921628&loc=SL4569643-111683

+ Details