Derivative Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Derivative [Line Items]
Cash collateral received for derivative instruments	$ 2,580,000,000		$ 1,680,000,000
Cash collateral provided for derivative instruments	3,360,000,000		1,300,000,000
Fair value of derivative liabilities	11,811,000,000	[1]	9,438,000,000	[1]
Weighted average life of trusts (in years)	6 years 6 months		6 years 11 months
Fair Value Hedges | 1.35% Senior Note
Derivative [Line Items]
Fixed interest rate	1.35%
Fair Value Hedges | 3.70% senior notes due in 2023
Derivative [Line Items]
Fixed interest rate	3.70%
Cash Flow Hedges
Derivative [Line Items]
Securities weighted average life (in years)	10 months		1 year 9 months
Credit swap agreements
Derivative [Line Items]
Cash collateral provided for derivative instruments	11,000,000
Fair value of derivative liabilities	565,000,000
Maximum additional amount of payments related to termination events	$ 554,000,000
Interest rate swap | Fair Value Hedges | 3.1% Subordinated Note
Derivative [Line Items]
Fixed interest rate	3.10%
Interest rate swap | Senior notes | Fair Value Hedges
Derivative [Line Items]
Number of securities	2
Interest rate swap | Subordinated note | Fair Value Hedges
Derivative [Line Items]
Number of securities	1

[1] Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.