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Long-Term Debt (Details 1) (USD $) | Sep. 30, 2014 2.25% Convertible Senior Notes due 2036 [Member] | Sep. 02, 2014 2.25% Convertible Senior Notes due 2036 [Member] | Dec. 31, 2013 2.25% Convertible Senior Notes due 2036 [Member] | Sep. 30, 2014 3.00% Convertible Senior Notes due 2020 [Member] | Jun. 25, 2014 3.00% Convertible Senior Notes due 2020 [Member] | Dec. 31, 2013 3.00% Convertible Senior Notes due 2020 [Member]
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Carrying value of Notes related discount and equity component |  |  |  |  |  |
Debt Instrument, Face Amount | $ 182,800,000 | $ 182,500,000 |  |  | $ 115,000,000 |
Secured Long-term Debt, Noncurrent | $ 0 |  | $ 160,334,000 | $ 0 |  | $ 84,305,000

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- Definition Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets. + 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) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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