Securities Available for Sale (Tables)

3 Months Ended

Mar. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Securities Portfolio Composition

	March 31, 2016
(Dollars in millions)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
U.S. Treasury securities		$3,694		$103		$—		$3,797
Federal agency securities	377		12		—		389
U.S. states and political subdivisions	149		9		—		158
MBS - agency	22,615		589		14		23,190
MBS - non-agency residential	88		1		1		88
ABS	10		2		1		11
Corporate and other debt securities	36		1		—		37
Other equity securities 1	518		1		1		518
Total securities AFS		$27,487		$718		$17		$28,188
	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 March 31, 2016, the fair value of other equity securities was comprised of the following: $64 million of FHLB of Atlanta stock, $402 million of Federal Reserve Bank of Atlanta stock, $47 million of mutual fund investments, and $5 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 March 31
(Dollars in millions)	2016		2015
Taxable interest		$159		$128
Tax-exempt interest	1		2
Dividends	3		10
Total interest and dividends on securities AFS		$163		$140

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		$—			$1,371			$2,323			$—			$3,694
Federal agency securities	142			106			13			116			377
U.S. states and political subdivisions	29			6			100			14			149
MBS - agency	2,252			8,598			8,113			3,652			22,615
MBS - non-agency residential	—			88			—			—			88
ABS	2			6			2			—			10
Corporate and other debt securities	—			36			—			—			36
Total debt securities AFS		$2,425			$10,211			$10,551			$3,782			$26,969
Fair Value:
U.S. Treasury securities		$—			$1,395			$2,402			$—			$3,797
Federal agency securities	144			113			13			119			389
U.S. states and political subdivisions	30			6			108			14			158
MBS - agency	2,368			8,828			8,280			3,714			23,190
MBS - non-agency residential	—			88			—			—			88
ABS	3			7			1			—			11
Corporate and other debt securities	—			37			—			—			37
Total debt securities AFS		$2,545			$10,474			$10,804			$3,847			$27,670
Weighted average yield 1	2.50		%	2.35		%	2.69		%	2.91		%	2.57		%

¹ Weighted average yields are based on amortized cost and are presented on an FTE basis.

Securities in a Continuous Unrealized Loss Position

	March 31, 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		$10		$—		$34		$—		$44		$—
MBS - agency	859		3		1,613		11		2,472		14
ABS	—		—		6		1		6		1
Other equity securities	3		1		—		—		3		1
Total temporarily impaired securities AFS	872		4		1,653		12		2,525		16
OTTI securities AFS 1:
MBS - non-agency residential	51		1		—		—		51		1
ABS	1		—		—		—		1		—
Total OTTI securities AFS	52		1		—		—		52		1
Total impaired securities AFS		$924		$5		$1,653		$12		$2,577		$17

	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.