Asset Quality (Details 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Concession types for our commercial accruing and nonaccruing TDRs
Interest rate reduction	$ 155	$ 177	$ 175
Forgiveness of principal	13	23	10
Other modification of loan terms	20	8	6
Total	188	208	191
Total commercial and consumer TDRs	274	276	252
Total commercial TDRs to total commercial loans	0.54%	0.60%	0.58%
Total commercial TDRs to total loans	0.38%	0.42%	0.40%
Total commercial loans	34,603	34,782	32,688
Total loans	$ 49,605	$ 49,575	$ 47,840