Investment Securities (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 security country	Dec. 31, 2012	Dec. 31, 2011
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	$ 23,000,000	$ 32,000,000	$ 73,000,000
Impairment associated with adverse changes in timing of expected future cash flows	6,000,000	16,000,000	23,000,000
Impairment associated with management's intent to sell impaired securities prior to recovery in value	6,000,000	0	8,000,000
Impairment associated with expected credit losses	11,000,000	16,000,000	42,000,000
Number of peripheral european countries	4
Gross pre-tax unrealized losses on securities	(1,680,000,000)
Number of available for sale and held to maturity securities in gross pre-tax unrealized loss position	2,555
Pledged Financial Instruments, Not Separately Reported, Securities	46,990,000,000	46,660,000,000
U.S. agency residential mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	0	0
Non-U.S. debt securities, mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	12,000,000	22,000,000
Impairment associated with adverse changes in timing of expected future cash flows		16,000,000
Impairment associated with expected credit losses		6,000,000
Non-U.S. debt securities, mortgage-backed securities | European Periphery
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	6,000,000
Total exposure to asset backed securities	574,000,000
Aggregate pre-tax gross unrealized gain (loss) on available for sale securities	69,000,000
Available for sale, gross unrealized gains	84,000,000
Available for sale, gross unrealized losses	(15,000,000)
Non-U.S. debt securities, mortgage-backed securities | Spain
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Total exposure to asset backed securities	271,000,000
Non-U.S. debt securities, mortgage-backed securities | Italy
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Total exposure to asset backed securities	105,000,000
Non-U.S. debt securities, mortgage-backed securities | Ireland
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Total exposure to asset backed securities	120,000,000
Non-U.S. debt securities, mortgage-backed securities | Portugal
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Total exposure to asset backed securities	78,000,000
Asset-backed securities, student loans
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	0	0
Federal Family Education Loan Program
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Federal government credit support guarantee, percentage minimum	97.00%
Collective credit support, percentage minimum	100.00%
Average remaining term	4 years 10 months 24 days
Maximum concentration risk on credit instruments (less than)	900,000,000
Direct sovereign debt
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Total exposure to asset backed securities	0
State and political subdivisions
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	0	0
U.S. non-agency residential mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded		10,000,000
Collateralized mortgage obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Other-than-temporary impairment recorded	$ 11,000,000
Minimum
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Percentage change in additional house price declines	12.00%
Maximum
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Percentage change in additional house price declines	19.00%