Debt (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Long-term debt
0.94% senior exchangeable notes due May 2011	$ 0	$ 1,378,178
Revolving credit facilities outstanding	1,150,000
Other	1,200,000	0
Long-term Debt	4,265,467	4,443,144
Current portion of long-term debt	881	1,379,018
Long-term debt, Noncurrent	4,264,586	3,064,126
6.15% Senior Notes Due February 2018 [Member]
Long-term debt
Senior Notes	966,883	966,276
9.25% Senior Notes Due January 2019 [Member]
Long-term debt
Senior Notes	1,125,000	1,125,000
5.00% senior notes due September 2020 [Member]
Long-term debt
Senior Notes	697,190	697,037
5.375% Senior Notes Due August 2012 [Member]
Long-term debt
Senior Notes	274,291	273,977
Revolving Credit Facility [Member]
Long-term debt
Revolving credit facilities outstanding	$ 2,103	$ 2,676

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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Amount borrowed under the credit facility as of the balance sheet date.

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Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. 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, and after deducting unamortized discount or premiums, if any.

+ References

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Total of the portions of the carrying amounts as of the balance sheet date of long-term debt, which may include notes payable, bonds payable, debentures, mortgage loans, and commercial paper, which are scheduled to be repaid within one year or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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