Fair Value Measurement - Impact of Credit Adjustments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Credit Valuation Adjustment
Impact of credit adjustments on earnings [Abstract]
Derivative credit adjustments	$ 181	$ (19)
Debit Valuation Adjustment and Funding Valuation Adjustment
Impact of credit adjustments on earnings [Abstract]
Derivative credit adjustments	(141)	(125)
Structured note credit adjustments	148	17
Debit Valuation Adjustment
Impact of credit adjustments on earnings [Abstract]
Derivative credit adjustments	13	(94)
Structured note credit adjustments	$ 108	$ (115)