Securities Available for Sale (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 21,087		$ 25,170
Unrealized Gains	880		2,989
Unrealized Losses	14		42
Available-for-sale Securities	21,953		28,117
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	212		671
Unrealized Gains	10		23
Unrealized Losses	0		0
Available-for-sale Securities	222		694
US Government Agencies Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,987		1,843
Unrealized Gains	85		89
Unrealized Losses	3		0
Available-for-sale Securities	2,069		1,932
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	310		437
Unrealized Gains	15		21
Unrealized Losses	5		4
Available-for-sale Securities	320		454
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,416		20,480
Unrealized Gains	756		743
Unrealized Losses	3		0
Available-for-sale Securities	18,169		21,223
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	205		252
Unrealized Gains	4		0
Unrealized Losses	0		31
Available-for-sale Securities	209		221
Collateralized Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			50
Unrealized Gains			0
Unrealized Losses			0
Available-for-sale Securities			50
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	214		460
Unrealized Gains	5		11
Unrealized Losses	3		7
Available-for-sale Securities	216		464
Corporate And Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42		49
Unrealized Gains	4		2
Unrealized Losses	0		0
Available-for-sale Securities	46		51
Equity Securities, Coca Cola
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			0
Unrealized Gains			2,099
Unrealized Losses			0
Available-for-sale Securities			2,099
Equity Securities, Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	701	[1]	928	[1]
Unrealized Gains	1	[1]	1	[1]
Unrealized Losses	0	[1]	0	[1]
Available-for-sale Securities	$ 702	[1]	$ 929	[1]

[1] At December 31, 2012, other equity securities was comprised of the following: $229 million in FHLB of Atlanta stock, $402 million in Federal Reserve Bank stock, $69 million in mutual fund investments, and $2 million of other. At December 31, 2011, other equity securities was comprised of the following: $342 million in FHLB of Atlanta stock, $398 million in Federal Reserve Bank stock, $187 million in mutual fund investments, and $2 million of other.