Debt (Recourse Debt Net Principal Amounts Due Over Five Years) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Debt Details [Line Items]
Recourse Debt Total	$ 5,669	$ 5,962
2014
Debt Details [Line Items]
Recourse Debt Total	118
2015
Debt Details [Line Items]
Recourse Debt Total	364
2016
Debt Details [Line Items]
Recourse Debt Total	368
2017
Debt Details [Line Items]
Recourse Debt Total	1,158
2018
Debt Details [Line Items]
Recourse Debt Total	764
Thereafter
Debt Details [Line Items]
Recourse Debt Total	$ 2,897