Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Convertible Notes Payable, excluding current portion. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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Carrying value as of the balance sheet date of the portion of long-term debt due within one year or the operating cycle if longer identified as Convertible Notes Payable. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

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The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Convertible Notes (Schedule of Notes) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Convertible notes	Dec. 31, 2012 Convertible notes	Dec. 31, 2013 Convertible notes 1.125% Convertible Senior Notes due 2018	Aug. 16, 2013 Convertible notes 1.125% Convertible Senior Notes due 2018	Dec. 31, 2012 Convertible notes 1.125% Convertible Senior Notes due 2018	Dec. 31, 2013 Convertible notes 5% Convertible Senior Notes due 2014	Dec. 31, 2012 Convertible notes 5% Convertible Senior Notes due 2014	Jun. 29, 2009 Convertible notes 5% Convertible Senior Notes due 2014
Debt Instrument [Line Items]
Face Value			$ 310,500	$ 172,500	$ 138,000	$ 138,000	$ 0	$ 172,500	$ 172,500	$ 150,000
Unamortized discount	(36,824)	(24,944)			(28,371)		0	(8,453)	(24,944)
Total convertible notes	273,676	147,556
Less current portion	164,047	0
Total long-term convertible notes	$ 109,629	$ 147,556