Represents the threshold of original maturity used to distinguish short and long-term investments.

No definition available.

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- Definition

Represents the maximum term of maturity to classify highly liquid interest earning investments as cash equivalent.

+ References

No definition available.

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- Definition

Represents the minimum term of maturity to classify an investment as short-term investment.

+ References

No definition available.

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- Definition

Represents the number of geographic operating segments of the entity.

+ References

No definition available.

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 07-4

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Diluted Earnings Per Share

-URI http://asc.fasb.org/extlink&oid=6510752

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Contingent Stock Agreement

-URI http://asc.fasb.org/extlink&oid=6508534

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Antidilution

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 171

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 40

-Subparagraph c

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-Topic 260

-SubTopic 10

-Section 50

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-Subparagraph (c)

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 13, 14

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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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- Definition

The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8

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-Name FASB Staff Position (FSP)

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-Paragraph 18B

-Subparagraph a

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Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 Segment	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 2.625% convertible senior notes due 2019	Dec. 31, 2012 2.625% convertible senior notes due 2019	Dec. 17, 2012 2.625% convertible senior notes due 2019
Summary of Significant Accounting Policies
Number of geographic segments	2
Investments
Maximum term of maturity to classify highly liquid interest earning investments as cash equivalent	3 months
Minimum term of maturity to classify an investment as short-term investment	3 months
Maximum term of maturity to classify an investment as short-term investment	1 year
OTTI in debt securities	$ 0		$ 0
Earnings (Loss) Per Share
Shares of non-vested restricted stock, non vested restricted stock units, outstanding stock options and 2.625% convertible senior notes due 2019 excluded from the diluted income (loss) per share calculation	6,848,139	6,595,786
Earnings (Loss) Per Share
Interest rate (as a percent)			2.625%	2.625%	2.625%	2.625%