Borrowings and Bank Deposits (Long-term Debt Maturities) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Debt Disclosure [Abstract]
2013	$ 44,264,000,000
2014	38,783,000,000
2015	36,252,000,000
2016	23,047,000,000
2017	24,775,000,000
Fixed and floating rate notes containing put options	914,000,000
Banks extending committed credit lines	51
Committed credit lines	48,200,000,000
Revolving credit agreements	30,300,000,000
Three hundred sixty four day revolving credit agreement	17,900,000,000
Extension Period From Date Of Expiration In Term Out Feature Minimum	one
Extension Period From Date Of Expiration In Term Out Feature Maximum	two
Borrowings And Bank Deposits [Line Items]
Committed Credit Lines	48,200,000,000
Parent Company [Member]
Debt Disclosure [Abstract]
Committed credit lines	12,000,000,000
Borrowings And Bank Deposits [Line Items]
Committed Credit Lines	$ 12,000,000,000