Derivatives (Details 1) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Forward delivery commitments subject to netting arrangements
Asset Derivatives	$ 131	$ 409
Liability Derivatives	88	182
Other Assets [Member] | Forward delivery commitments [Member]
Forward delivery commitments subject to netting arrangements
Asset Derivatives	15	10
Liability Derivatives	17	3
Other Liabilities [Member] | Forward delivery commitments [Member]
Forward delivery commitments subject to netting arrangements
Asset Derivatives	15	238
Liability Derivatives	17	65
Forward delivery commitments [Member]
Forward delivery commitments subject to netting arrangements
Asset Derivatives	30	248
Liability Derivatives	$ 34	$ 68