Financings (Contingently Convertible Securities) (Details) (USD $)	9 Months Ended
Sep. 30, 2011
Number of trading days, adjusted trigger price contingencies were met	20
Number of trading days	30
2.875% Senior Notes [Member]
Maturity Date	2024
Outstanding	$ 288,000,000
Adjusted Conversion Price	$ 12.67
Adjusted Trigger Price	$ 15.20
Senior Notes Interest Rate	2.875%
5.50% Senior Notes [Member]
Maturity Date	2029
Outstanding	172,000,000
Adjusted Conversion Price	$ 14.26
Adjusted Trigger Price	$ 18.54
Senior Notes Interest Rate	5.50%
3.375% Contingently Convertible Senior Notes due 2023 [Member]
Senior Notes Interest Rate	3.375%
Conversion Date	January 2011
Principal Converted	4,000,000
Conversion Value per share of principal	1,994.21
Common Stock Issued on Settlement	197,472
Cash Paid on Settlement	$ 4,000,000

The price of the company's common stock which would be required to be attained for the conversion feature imbedded in the debt instrument to become effetive.

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Conversion Date

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Number of trading days

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Number of trading days, adjusted trigger price contingencies were met

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Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

+ References

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

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-Name Accounting Standards Codification

-Topic 942

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The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 32

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The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

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The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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The price per share of the conversion feature embedded in the debt instrument.

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Interest rate stated in the contractual debt agreement.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

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The cash outflow from the repayment of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

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