Long-Term Debt (8.0% Senior Notes, Due 2019 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]	Mar. 31, 2012 Senior Notes at 8.0, Due 2019 [Member]	Nov. 30, 2011 Senior Notes at 8.0, Due 2019 [Member]	Nov. 30, 2011 Period prior to November 15, 2014 with Redemption Limited to Using Proceeds from Public Equity Offering [Member] Senior Notes at 8.0, Due 2019 [Member]	Nov. 30, 2011 Period Prior To November 15, 2015 [Member] Senior Notes at 8.0, Due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jul. 15, 2015			Nov. 15, 2019	Nov. 15, 2019
Debt Instrument Offering Date 1				Mar. 21, 2012	Nov. 22, 2011
Debt Instrument, Face Amount	$ 3,000,000,000			$ 1,000,000,000	$ 1,000,000,000
Extinguishment of Debt, Amount		$ 850,000,000	$ 1,000,000,000
Debt Instrument, Premium Percentage				102.50%
Debt Instrument, Interest Rate, Stated Percentage	8.875%			8.00%	8.00%
Debt Instrument, Earliest Redemption Date	Jul. 15, 2011				Nov. 15, 2015	Nov. 15, 2014	Nov. 15, 2015
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						108.00%	100.00%
Maximum Principal Redeemable Using Proceeds from a Public Equity Offering, as a Percentage of Principal Amount						35.00%