Fair Value of Assets and Liabilities (Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Derivative Assets	$ 1,138		$ 533
Derivative Liabilities	541		2,156
Fair Value, Inputs, Level 1 [Member]
Derivative Assets	12		25
Derivative Liabilities	5		6
Fair Value, Inputs, Level 2 [Member]
Derivative Assets	8,825		7,741
Derivative Liabilities	7,588		9,402
Fair Value, Inputs, Level 3 [Member]
Derivative Assets	15		8
Derivative Liabilities	3		5
Netting And Collateral [Member]
Derivative Assets	(7,714)		(7,241)
Derivative Liabilities	(7,055)		(7,257)
Derivative, Collateral, Obligation to Return Cash	659		(16)
Interest Rate Contract [Member]
Derivative Assets	7,567		6,140
Derivative Liabilities	6,104		7,607
Interest Rate Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	2		10
Derivative Liabilities	4		5
Interest Rate Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	7,556		6,122
Derivative Liabilities	6,097		7,597
Interest Rate Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	9		8
Derivative Liabilities	3		5
Interest Rate Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Foreign Exchange Contract [Member]
Derivative Assets	311		593
Derivative Liabilities	147		425
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	311		593
Derivative Liabilities	147		425
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Foreign Exchange Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Credit Risk Contract [Member]
Derivative Assets	6		3
Derivative Liabilities	38		49
Credit Risk Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Credit Risk Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	6		3
Derivative Liabilities	38		49
Credit Risk Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Credit Risk Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Cross Currency Interest Rate Contract [Member]
Derivative Assets	532		647
Derivative Liabilities	949		857
Cross Currency Interest Rate Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Cross Currency Interest Rate Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	532		647
Derivative Liabilities	949		857
Cross Currency Interest Rate Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Cross Currency Interest Rate Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Equity Contract [Member]
Derivative Assets	435		390
Derivative Liabilities	357		475
Equity Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	9		14
Derivative Liabilities	0		1
Equity Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	420		376
Derivative Liabilities	357		474
Equity Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	6		0
Derivative Liabilities	0		0
Equity Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Commodity Contract [Member]
Derivative Assets	1		1
Derivative Liabilities	1		0
Commodity Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	1		1
Derivative Liabilities	1		0
Commodity Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Commodity Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Commodity Contract [Member] | Netting And Collateral [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Prudential, Netting Agreement [Member]
Derivative Assets	(7,714)	[1]	(7,241)	[1]
Derivative Liabilities	(7,055)	[1]	(7,257)	[1]
Prudential, Netting Agreement [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Prudential, Netting Agreement [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Prudential, Netting Agreement [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative Assets	0		0
Derivative Liabilities	0		0
Prudential, Netting Agreement [Member] | Netting And Collateral [Member]
Derivative Assets	(7,714)	[1]	(7,241)	[1]
Derivative Liabilities	$ (7,055)	[1]	$ (7,257)	[1]

[1] “Netting” amounts represent cash collateral and the impact of offsetting asset and liability positions held with the same counterparty.