Consolidated Condensed Statement of Equity (Parenthetical)	3 Months Ended
Mar. 31, 2012
Consolidated Condensed Statement of Equity [Abstract]
Stock options exercised (in shares)	22,095
Conversions from Class B to common stock (in shares)	1,153,322

Number of shares issued during the period as a result of the conversion of convertible securities.

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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

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-Name Regulation S-X (SX)

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

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-Name Statement of Financial Accounting Standard (FAS)

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 5: http://www.xbrl.org/2003/role/presentationRef

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

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-Name Regulation S-X (SX)

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

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-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

+ Details

- Definition

Number of share options (or share units) exercised during the current period.

+ References+ Details