Debt Recourse Debt (Details) (USD $)	1 Months Ended	2 Months Ended	3 Months Ended		6 Months Ended								3 Months Ended
	May 31, 2013	Jul. 31, 2013	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	May 17, 2013 4.875% Senior Notes Due 2023 [Member]	Apr. 29, 2013 4.875% Senior Notes Due 2023 [Member]	Jun. 30, 2013 7.75% Senior Notes Due 2014 [Member]	Jun. 30, 2013 7.75% Senior Notes Due 2015 [Member]	Jun. 30, 2013 9.75% Senior Notes Due 2016 [Member]	Jun. 30, 2013 8.0% Senior Notes Due 2017 [Member]	Jun. 30, 2013 Recourse Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 750,000,000		$ 750,000,000		$ 250,000,000	$ 500,000,000
Debt Instrument, Term			10 years
Debt Instrument, Interest Rate, Stated Percentage							4.875%	4.875%	7.75%	7.75%	9.75%	8.00%
Extinguishment of Debt, Amount	928,000,000	122,000,000	300,000,000
Loss on extinguishment of debt			$ (165,000,000)	$ 0	$ (212,000,000)	$ 0							$ 163,000,000