Acquisitions/Dispositions Acquisitions/Dispositions-Additional Detail (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Corporate Other [Member]	Sep. 30, 2013 Corporate Other [Member]	Sep. 30, 2014 Corporate Other [Member]	Sep. 30, 2013 Corporate Other [Member]	Sep. 30, 2014 Ridgeworth Capital Management [Member] Corporate Other [Member]	Sep. 30, 2013 Ridgeworth Capital Management [Member] Corporate Other [Member]	Dec. 31, 2013 Ridgeworth Capital Management [Member] Corporate Other [Member]	Jun. 30, 2014 Ridgeworth Capital Management [Member]	May 30, 2014 Ridgeworth Capital Management [Member]
Significant Acquisitions and Disposals [Line Items]
Stockholders' Equity Attributable to Noncontrolling Interest												$ 0
Assets under Management, Carrying Amount													49,100,000,000
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	679,000,000	95,000,000	1,860,000,000	1,211,000,000	74,000,000	112,000,000	351,000,000	362,000,000	22,000,000	49,000,000	64,000,000
Revenues									81,000,000	145,000,000	194,000,000
Noninterest Expense	$ 1,259,000,000	$ 1,730,000,000	$ 4,134,000,000	$ 4,470,000,000	$ 11,000,000	$ 22,000,000	$ 91,000,000	$ 58,000,000	$ 59,000,000	$ 96,000,000	$ 130,000,000