Debt Repayments of Principal and Interest (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Secured Debt	$ 18,447
Unsecured Debt	5,228	1,500
Interest Payable	1,461
Repayments of Principal and Interest	25,136
Fiscal 2013 [Member]
Secured Debt	3,672
Unsecured Debt	724
Interest Payable	152
Repayments of Principal and Interest	4,548
Fiscal 2014 [Member]
Secured Debt	6,334
Unsecured Debt	306
Interest Payable	451
Repayments of Principal and Interest	7,091
Fiscal 2015 [Member]
Secured Debt	4,239
Unsecured Debt	166
Interest Payable	308
Repayments of Principal and Interest	4,713
Fiscal 2016 [Member]
Secured Debt	2,686
Unsecured Debt	1,032
Interest Payable	211
Repayments of Principal and Interest	3,929
Fiscal 2017 [Member]
Secured Debt	1,217
Unsecured Debt	1,000
Interest Payable	143
Repayments of Principal and Interest	2,360
Thereafter [Member]
Secured Debt	299
Unsecured Debt	2,000
Interest Payable	196
Repayments of Principal and Interest	$ 2,495