Investment Securities (Contractual Maturity Distribution Of Debt Securities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Within one year, Amortized Cost	$ 154
After one year through five years, Amortized Cost	287
After five years through ten years, Amortized Cost	294
After ten years, Amortized Cost	8,538
Subtotal, Amortized Cost	9,273
Within one year, Fair Value	154
After one year through five years, Fair Value	289
After five years through ten years, Fair Value	306
After ten years, Fair Value	8,535
Subtotal, Fair Value	9,284
Total investment securities available-for-sale, Amortized Cost	9,526	[1]	9,414	[1]
Total investment securities available-for-sale, Fair Value	9,534	[1]	9,307	[1]
Equity and Other Non-Debt Securities
Total investment securities available-for-sale, Amortized Cost	253		266
Total investment securities available-for-sale, Fair Value	$ 250		$ 258

[1] Included auction-rate securities at amortized cost and fair value of $145 million and $142 million, respectively, as of June 30, 2014 and $169 million and $159 million, respectively, as of December 31, 2013.