Acquisitions/Dispositions Acquisitions/Dispositions-Additional Detail (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended				12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Corporate Other [Member]	Jun. 30, 2013 Corporate Other [Member]	Jun. 30, 2014 Corporate Other [Member]	Jun. 30, 2013 Corporate Other [Member]	Jun. 30, 2014 Ridgeworth Capital Management [Member] Corporate Other [Member]	Jun. 30, 2013 Ridgeworth Capital Management [Member] Corporate Other [Member]	Dec. 31, 2013 Ridgeworth Capital Management [Member] Corporate Other [Member]
Significant Acquisitions and Disposals [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 611	$ 567	$ 1,182	$ 1,116	$ 189	$ 146	$ 281	$ 251	$ 22	$ 32	$ 64
Revenues									81	96	194
Noninterest Expense	1,517	1,387	2,874	2,740	34	1	77	35	59	64	130
Income (Loss) from Continuing Operations Attributable to Parent									20
Income (Loss) Attributable to Noncontrolling Interest									$ 2