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Consolidating Financial Statements (Details Textual)	Dec. 31, 2011
On conversion of 4.75% convertible senior notes due 2014 [Member]
Financial Statements (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	4.75%
On conversion of 7.25% convertible Senior notes due 2018 [Member]
Financial Statements (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.25%

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- Definition

Interest rate stated in the contractual debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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

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