Fair Value Measurements Unobservable Inputs (Details) (Convertible Notes due December 15, 2017 [Member], USD $)	12 Months Ended
Dec. 31, 2013
Convertible Notes due December 15, 2017 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Share Price	$ 14.77
Fair Value Assumptions, Expected Volatility Rate	27.20%
Fair Value Inputs, Entity Credit Risk	7.25%
Fair Value Assumptions, Risk Free Interest Rate	1.24%

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

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- Definition

Risk associated with risk of default, credit spread risk and downgrade risk, expressed as a percentage, used as an input to measure fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

+ Details

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