Investment Securities - Schedule of Investment Portfolio (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Securities available for sale, at fair value	$ 39,665	$ 41,800
Securities held to maturity, at carrying value	22,182	19,132
Total investments	$ 61,847	$ 60,932

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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