Quarterly Financial Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Quarterly Financial Information [Abstract]
Net Revenues	$ 1,435		$ 1,373		$ 1,337		$ 1,290		$ 1,215		$ 1,196		$ 1,283		$ 1,189		$ 5,435		$ 4,883		$ 4,691
Expenses Excluding Interest	937		909		925		959		871		835		851		876		3,730		3,433		3,299
Net Income	319		290		256		206		211		247		275		195		1,071		928		864
Net Income Available to Common Stockholders	$ 297		$ 282		$ 233		$ 198		$ 189		$ 238		$ 261		$ 195		$ 1,010		$ 883		$ 864
Weighted Average Common Shares Outstanding - Diluted	1,304		1,296		1,288		1,282		1,278		1,275		1,274		1,273		1,293	[1]	1,275	[1]	1,229	[1]
Earnings Per Common Share - Basic	$ 0.23		$ 0.22		$ 0.18		$ 0.15		$ 0.15		$ 0.19		$ 0.20		$ 0.15		$ 0.78		$ 0.69		$ 0.70
Earnings Per Common Share - Diluted	$ 0.23		$ 0.22		$ 0.18		$ 0.15		$ 0.15		$ 0.19		$ 0.20		$ 0.15		$ 0.78		$ 0.69		$ 0.70
Dividends Declared Per Common Share	$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.24		$ 0.24		$ 0.24
Range of Common Stock Price Per Share:
High	$ 26.00		$ 22.69		$ 21.23		$ 18.11		$ 14.47		$ 14.43		$ 14.76		$ 15.38
Low	$ 20.57		$ 20.74		$ 16.21		$ 15.05		$ 12.50		$ 12.14		$ 11.83		$ 11.61
Range of Price/Earnings Ratio:
High	33	[2]	32	[2]	32	[2]	26	[2]	21	[2]	22	[2]	22	[2]	23	[2]
Low	26	[2]	30	[2]	24	[2]	22	[2]	18	[2]	18	[2]	18	[2]	18	[2]

[1] Antidilutive stock options and restricted stock awards excluded from the calculation of diluted EPS totaled 34 million, 74 million, and 63 million shares in 2013, 2012, and 2011, respectively.

[2] Price/earnings ratio is computed by dividing the high and low market prices by diluted earnings per common share for the preceding 12-month period ending on the last day of the quarter presented.