Long-Term Debt (7.125% Senior Notes, Due 2020 Narrative) (Details) (Senior Notes [Member], USD $)	1 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended
	Jul. 31, 2007 Senior Notes at 8.875, Due 2015 [Member]	Mar. 31, 2012 Senior Notes at 8.875, Due 2015 [Member]	Dec. 31, 2011 Senior Notes at 8.875, Due 2015 [Member]	Jul. 31, 2012 Senior Notes at 7.125, Due 2020 [Member]	Jul. 31, 2012 Period prior to July 15, 2015 with Redemption Limited to Using Proceeds from Public Equity Offering [Member] Senior Notes at 7.125, Due 2020 [Member]	Jul. 31, 2012 Period Prior To July, 15 2016 [Member] Senior Notes at 7.125, Due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Offering Date				Jul. 18, 2012
Debt Instrument, Face Amount	$ 3,000,000,000			$ 1,200,000,000
Extinguishment of Debt, Amount		$ 850,000,000	$ 1,000,000,000	$ 934,300,000
Debt Instrument, Interest Rate, Stated Percentage	8.875%			7.125%
Debt Instrument, Earliest Redemption Date	Jul. 15, 2011			Jul. 15, 2016	Jul. 15, 2015	Jul. 15, 2016
Minimum Period Notice for Redemption of Debt	30 days			30 days
Maximum Period Notice for Redemption of Debt	60 days			60 days
Period Subject to Redemption Price Commencing on Scheduled Date	12 months			12 months
Future Redemption Price of Debt During Eligibility Period, as a Percentage of Principal Amount					107.125%	100.00%
Max Principal Redeemable Using Proceeds from a Public Equity Offering, as a Percentage of Principal Amount					35.00%