Federal Funds Sold and Securities Borrowed or Purchased Under Agreements to Resell Netting of financial instruments - repurchase agreements (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value of Securities Purchased under Agreements to Resell and Deposits Paid for Securities Borrowed	$ 907		$ 908
Securities Purchased under Agreements to Resell, Amount Offset Against Collateral	0		0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	907	[1]	908	[1],[2]
Held Financial Instruments, Not Separately Reported, Securities for Reverse Repurchase Agreements	896		899
Securities Borrowed or Purchased Under Agreements to Resell, Amount Not Offset Against Collateral	11		9
Carrying Value of Securities Sold under Repurchase Agreements and Deposits Received for Securities Loaned	2,133		1,759
Securities Sold Under Agreements to Repurchase, Amount Offset Against Collateral	0		0
Securities Sold under Agreements to Repurchase	2,133	[1]	1,759	[1]
Pledged Financial Instruments, Not Separately Reported, Securities for Repurchase Agreements	2,133		1,759
Securities Sold Under Agreements to Repurchase, Amount Not Offset Against Collateral	$ 0		$ 0

[1] None of the Company's repurchase and reverse repurchase transactions met the right of setoff criteria for net balance sheet presentation at March 31, 2014 and December 31, 2013.

[2] Excludes $75 million of Fed funds sold which are not subject to a master netting agreement at December 31, 2013