Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Weighted Average Life Interest Only Securities	6 years 6 months	6 years 4 months
Weighted Average Life Principal Only Securities	8 years 9 months	8 years 7 months
Agency securities classified as available for sale, Fair value	$ 53,127	$ 65,504
Agency securities classified as available for sale, Amortized cost	52,904	66,593
Weighted average coupon	3.51%	3.47%
Available For Sale Securities Weighted Average Life yield	2.68%	2.68%
Less Than or Equal to One Year [Member]
Available For Sale Securities Weighted Average Life Fair Value	93	129
Available For Sale Securities Weighted Average Life Amortized Cost	90	129
Weighted average coupon	2.66%	3.07%
Available For Sale Securities Weighted Average Life yield	2.31%	2.53%
Greater Than One Year and Less Than or Equal to Three Years [Member]
Available For Sale Securities Weighted Average Life Fair Value	163	498
Available For Sale Securities Weighted Average Life Amortized Cost	158	491
Weighted average coupon	4.61%	4.08%
Available For Sale Securities Weighted Average Life yield	3.26%	2.25%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Available For Sale Securities Weighted Average Life Fair Value	22,395	24,471
Available For Sale Securities Weighted Average Life Amortized Cost	22,042	24,342
Weighted average coupon	3.46%	3.59%
Available For Sale Securities Weighted Average Life yield	2.46%	2.57%
Greater Than Five Years [Member]
Available For Sale Securities Weighted Average Life Fair Value	29,833	38,522
Available For Sale Securities Weighted Average Life Amortized Cost	29,955	39,635
Weighted average coupon	3.54%	3.39%
Available For Sale Securities Weighted Average Life yield	2.82%	2.73%
Greater Than Ten Years [Member]
Available For Sale Securities Weighted Average Life Fair Value	643	1,884
Available For Sale Securities Weighted Average Life Amortized Cost	$ 659	$ 1,996
Weighted average coupon	3.82%	3.66%
Available For Sale Securities Weighted Average Life yield	2.99%	2.96%