Decrease for amounts repaid on the debt instrument for the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph f
-Article 4

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
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Interest rate stated in the contractual debt agreement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
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Amount of the required periodic payments including both interest and principal payments. (Consider the frequency of payment.)

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-Name Regulation S-X (SX)
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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Description of long-term debt arrangements, which are debt arrangements that originally require full repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer, and disclosures pertaining to the underlying arrangements, including repayment terms, conversion features, interest rates, restrictions on assets and activities, debt covenants, and other matters important to users of the financial statements. Types of long-term debt arrangements include borrowing under notes payable, bonds payable, debentures, term loans, and other contractual obligations for payment.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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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), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Debt.

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Make Whole On Redemption Of senior Notes.

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Debt (Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Mar. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
5-year term loan facility [Member]
Debt (Textuals) [Abstract]
Number of years of loan facility		5 years
Interest of loan facility		LIBOR plus 2.250%
Repayable of term loan Per Quarter		$ 27
Repayable of term loan in Last Quarter of 2013		115
Revolving $300 million credit facility [Member]
Debt (Textuals) [Abstract]
Revolving credit facility		300
6.000% loan notes due 2012 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		6.00%
5.625% senior notes due 2015 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		5.625%
Long-term debt		350	350
12.875% senior notes due 2016 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		12.875%
Long-term debt		0	500
Redemption of senior notes	465	35
Make-whole on repurchase of senior notes		146
Make-whole on redemption of senior notes	12
Write off of unamortized debt issuance costs associated with debt repurchase	13
4.125% senior notes due 2016 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		4.125%
Effective interest rate		4.24%
Long-term debt		299	0
6.200% senior notes due 2017 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		6.20%
Long-term debt		600	600
7.000% senior notes due 2019 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		7.00%
Long-term debt		300	300
5.750% senior notes due 2021 [Member]
Debt (Textuals) [Abstract]
Percentage of loan notes		5.75%
Effective interest rate		5.871%
Long-term debt		$ 496	$ 0