Securities Available for Sale (Tables)

6 Months Ended

Jun. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Securities Portfolio Composition

	June 30, 2016
(Dollars in millions)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
U.S. Treasury securities		$4,273		$168		$—		$4,441
Federal agency securities	361		11		—		372
U.S. states and political subdivisions	164		11		—		175
MBS - agency	22,800		727		3		23,524
MBS - non-agency residential	82		1		—		83
ABS	9		2		—		11
Corporate and other debt securities	35		1		—		36
Other equity securities 1	694		1		1		694
Total securities AFS		$28,418		$922		$4		$29,336
	December 31, 2015
(Dollars in millions)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
U.S. Treasury securities		$3,460		$3		$14		$3,449
Federal agency securities	402		10		1		411
U.S. states and political subdivisions	156		8		—		164
MBS - agency	22,877		397		150		23,124
MBS - non-agency residential	92		2		—		94
ABS	11		2		1		12
Corporate and other debt securities	37		1		—		38
Other equity securities 1	533		1		1		533
Total securities AFS		$27,568		$424		$167		$27,825

¹ At June 30, 2016, the fair value of other equity securities was comprised of the following: $202 million of FHLB of Atlanta stock, $402 million of Federal Reserve Bank of Atlanta stock, $84 million of mutual fund investments, and $6 million of other.

At December 31, 2015, the fair value of other equity securities was comprised of the following: $32 million of FHLB of Atlanta stock, $402 million of Federal Reserve Bank of Atlanta stock, $93 million of mutual fund investments, and $6 million of other.

Investment Income [Table Text Block]

	Three Months Ended June 30				Six Months Ended June 30
(Dollars in millions)	2016		2015		2016		2015
Taxable interest		$156		$126		$315		$254
Tax-exempt interest	2		2		3		4
Dividends	3		9		6		19
Total interest and dividends on securities AFS		$161		$137		$324		$277

Amortized Cost and Fair Value of Investments in Debt Securities by Estimated Average Life

	Distribution of Remaining Maturities
(Dollars in millions)	Due in 1 Year or Less			Due After 1 Year through 5 Years			Due After 5 Years through 10 Years			Due After 10 Years			Total
Amortized Cost:
U.S. Treasury securities		$—			$1,646			$2,627			$—			$4,273
Federal agency securities	145			91			13			112			361
U.S. states and political subdivisions	26			16			89			33			164
MBS - agency	2,174			9,671			10,498			457			22,800
MBS - non-agency residential	—			82			—			—			82
ABS	1			8			—			—			9
Corporate and other debt securities	—			35			—			—			35
Total debt securities AFS		$2,346			$11,549			$13,227			$602			$27,724
Fair Value:
U.S. Treasury securities		$—			$1,685			$2,756			$—			$4,441
Federal agency securities	146			98			13			115			372
U.S. states and political subdivisions	26			17			98			34			175
MBS - agency	2,285			10,009			10,761			469			23,524
MBS - non-agency residential	—			83			—			—			83
ABS	1			10			—			—			11
Corporate and other debt securities	—			36			—			—			36
Total debt securities AFS		$2,458			$11,938			$13,628			$618			$28,642
Weighted average yield 1	2.50		%	2.40		%	2.56		%	3.04		%	2.50		%

¹ Weighted average yields are based on amortized cost.

Securities in a Continuous Unrealized Loss Position

	June 30, 2016
	Less than twelve months				Twelve months or longer				Total
(Dollars in millions)	Fair Value		Unrealized Losses 2		Fair Value		Unrealized Losses 2		Fair Value		Unrealized Losses 2
Temporarily impaired securities AFS:
Federal agency securities		$—		$—		$3		$—		$3		$—
MBS - agency	438		1		398		2		836		3
ABS	—		—		6		—		6		—
Other equity securities	4		1		—		—		4		1
Total temporarily impaired securities AFS	442		2		407		2		849		4
OTTI securities AFS 1:
MBS - non-agency residential	48		—		—		—		48		—
ABS	1		—		—		—		1		—
Total OTTI securities AFS	49		—		—		—		49		—
Total impaired securities AFS		$491		$2		$407		$2		$898		$4

	December 31, 2015
	Less than twelve months				Twelve months or longer				Total
(Dollars in millions)	Fair Value		Unrealized  Losses 2		Fair Value		Unrealized Losses		Fair Value		Unrealized  Losses 2
Temporarily impaired securities AFS:
U.S. Treasury securities		$2,169		$14		$—		$—		$2,169		$14
Federal agency securities	75		—		34		1		109		1
MBS - agency	11,434		114		958		36		12,392		150
ABS	—		—		7		1		7		1
Other equity securities	3		1		—		—		3		1
Total temporarily impaired securities AFS	13,681		129		999		38		14,680		167
OTTI securities AFS 1:
ABS	1		—		—		—		1		—
Total OTTI securities AFS	1		—		—		—		1		—
Total impaired securities AFS		$13,682		$129		$999		$38		$14,681		$167

¹ OTTI securities AFS are impaired securities for which OTTI credit losses have been previously recognized in earnings.

² Unrealized losses less than $0.5 million are presented as zero within the table.