Financing Arrangements (Details 2) (USD $) | 0 Months Ended | 3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|---|
Feb. 15, 2009 | Sep. 30, 2011 | Mar. 31, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | Dec. 31, 2010 | |
| Debt instruments: | |||||||
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 | $ 0.01 | ||||
1.5% Convertible Senior Notes due February 15, 2024 | |||||||
| Debt instruments: | |||||||
| Carrying value of the equity component | $ 19,515,000 | $ 19,515,000 | $ 21,181,000 | ||||
| Principal amount and carrying value of the liability component | 23,653,000 | 23,653,000 | 96,692,000 | ||||
| Common stock, par value (in dollars per share) | $ 0.01 | ||||||
| Notes convertible into common shares, conversion rate per $1,000 principal amount of Notes (in shares) | 36.2815 | ||||||
| 1.5% Convertible Senior Notes, principal amount (in dollars per unit) | $ 1,000 | ||||||
| Debt instrument, coupon interest | 100,000 | 400,000 | 400,000 | 1,100,000 | |||
| Effective interest rate of convertible debt instrument (as a percent) | 4.375% | ||||||
| Debt instrument, convertible, if-converted value | $ 40,000,000 | ||||||
| X | ||||||||||
- Definition The amount of the convertible debt's if-converted value at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.
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- Definition The amount of interest expense from the original coupon interest related to convertible debt instruments, which has been recognized for the period.
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- Definition The principal amount of the units of convertible debt to which the conversion ratio is applied.
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- Definition Face amount or stated value of common stock per share; generally not indicative of the fair market value per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The effective interest rate on the liability component of convertible debt instrument which may be settled in cash upon conversion, including partial cash settlement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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