Securities (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Amortized Cost, Gross Unrealized Gains, Gross Unrealized Losses, and Fair Values of Securities

At December 31, 2015 and 2014, the amortized cost, gross unrealized gains, gross unrealized losses, and fair values of securities are presented below.

	December 31, 2015
(Dollars in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Asset Liability Management securities:
U.S. Treasury	$	596	$	1	$	3	$	594
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	7,298		1		98		7,201
Privately issued	150		2		1		151
Privately issued - commercial mortgage-backed securities	1,566		5		25		1,546
Collateralized loan obligations	3,266		1		34		3,233
Other	7		—		—		7
Asset Liability Management securities	12,883		10		161		12,732
Other debt securities:
Direct bank purchase bonds	1,549		45		22		1,572
Other	32		—		—		32
Equity securities	6		2		—		8
Total securities available for sale	$	14,470	$	57	$	183	$	14,344

	December 31, 2014
(Dollars in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Asset Liability Management securities:
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	$	7,649	$	2	$	91	$	7,560
Privately issued	166		3		1		168
Privately issued - commercial mortgage-backed securities	1,689		15		13		1,691
Collateralized loan obligations	2,527		4		37		2,494
Other	8		1		—		9
Asset Liability Management securities	12,039		25		142		11,922
Other debt securities:
Direct bank purchase bonds	1,719		49		27		1,741
Other	53		—		1		52
Equity securities	8		2		1		9
Total securities available for sale	$	13,819	$	76	$	171	$	13,724

Securities in Unrealized Loss Position

The Company's securities available for sale with a continuous unrealized loss position at December 31, 2015 and 2014 are shown below, identified for periods less than 12 months and 12 months or more.

	December 31, 2015
	Less than 12 months				12 months or more				Total
(Dollars in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Asset Liability Management securities:
U.S. Treasury	$	295	$	3	$	—	$	—	$	295	$	3
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	4,692		57		2,278		41		6,970		98
Privately issued	39		—		38		1		77		1
Privately issued - commercial mortgage-backed securities	1,154		24		65		1		1,219		25
Collateralized loan obligations	1,497		11		1,290		23		2,787		34
Asset Liability Management securities	7,677		95		3,671		66		11,348		161
Other debt securities:
Direct bank purchase bonds	157		4		686		18		843		22
Other	2		—		—		—		2		—
Equity securities	—		—		5		—		5		—
Total securities available for sale	$	7,836	$	99	$	4,362	$	84	$	12,198	$	183

	December 31, 2014
	Less than 12 months				12 months or more				Total
(Dollars in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Asset Liability Management securities:
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	$	611	$	1	$	6,258	$	90	$	6,869	$	91
Privately issued	9		—		49		1		58		1
Privately issued - commercial mortgage-backed securities	143		—		842		13		985		13
Collateralized loan obligations	657		6		1,481		31		2,138		37
Other	—		—		1		—		1		—
Asset Liability Management securities	1,420		7		8,631		135		10,051		142
Other debt securities:
Direct bank purchase bonds	75		3		937		24		1,012		27
Other	—		—		22		1		22		1
Equity Securities	1		1		5		—		6		1
Total securities available for sale	$	1,496	$	11	$	9,595	$	160	$	11,091	$	171

The Company's securities held to maturity with a continuous unrealized loss position at December 31, 2015 and 2014 are shown below, separately for periods less than 12 months and 12 months or more.

	December 31, 2015
	Less than 12 months						12 months or more						Total
			Unrealized Losses						Unrealized Losses						Unrealized Losses
(Dollars in millions)	Fair Value		Recognized in OCI		Not Recognized in OCI		Fair Value		Recognized in OCI		Not Recognized in OCI		Fair Value		Recognized in OCI		Not Recognized in OCI
U.S. government-sponsored agencies	$	196	$	—	$	4	$	—	$	—	$	—	$	196	$	—	$	4
U.S. government agency and government-sponsored agencies—residential mortgage backed securities	3,297		—		39		1,705		53		2		5,002		53		41
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	197		—		1		1,428		73		4		1,625		73		5
Total securities held to maturity	$	3,690	$	—	$	44	$	3,133	$	126	$	6	$	6,823	$	126	$	50

	December 31, 2014
	Less than 12 months						12 months or more						Total
			Unrealized Losses						Unrealized Losses						Unrealized Losses
(Dollars in millions)	Fair Value		Recognized in OCI		Not Recognized in OCI		Fair Value		Recognized in OCI		Not Recognized in OCI		Fair Value		Recognized in OCI		Not Recognized in OCI
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	$	399	$	—	$	1	$	2,341	$	66	$	4	$	2,740	$	66	$	5
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	134		—		—		1,552		82		6		1,686		82		6
Total securities held to maturity	$	533	$	—	$	1	$	3,893	$	148	$	10	$	4,426	$	148	$	11

Debt Securities by Contractual Maturity

The fair value of debt securities available for sale by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.

	December 31, 2015
(Dollars in millions)	One Year or Less		Over One Year Through Five Years		Over Five Years Through Ten Years		Over Ten Years		Total Fair Value
Asset Liability Management securities:
U.S. Treasury	$	—	$	—	$	594	$	—	$	594
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	—		19		388		6,794		7,201
Privately issued	—		3		—		148		151
Privately issued - commercial mortgage-backed securities	—		—		36		1,510		1,546
Collateralized loan obligations	—		16		1,804		1,413		3,233
Other	—		2		5		—		7
Asset Liability Management securities	—		40		2,827		9,865		12,732
Other debt securities:
Direct bank purchase bonds	73		353		665		481		1,572
Other	—		1		—		31		32
Total debt securities available for sale	$	73	$	394	$	3,492	$	10,377	$	14,336

The carrying amount and fair value of securities held to maturity by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.

	December 31, 2015
	Over One Year Through Five Years				Over Five Years Through Ten Years				Over Ten Years				Total
(Dollars in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value
U.S. Treasury	$	489	$	493	$	—	$	—	$	—	$	—	$	489	$	493
U.S. government-sponsored agencies	—		—		220		216		—		—		220		216
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	—		—		99		100		7,683		7,690		7,782		7,790
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	49		50		799		835		819		823		1,667		1,708
Total securities held to maturity	$	538	$	543	$	1,118	$	1,151	$	8,502	$	8,513	$	10,158	$	10,207

Proceeds from Sales of Securities Available for Sale and Gross Realized Gains and Losses

The gross realized gains and losses from sales of available for sale securities for the years ended December 31, 2015, 2014 and 2013 are shown below. The specific identification method is used to calculate realized gains and losses on sales.

	For the Year Ended December 31,
(Dollars in millions)	2015		2014		2013
Gross realized gains	$	22	$	23	$	190
Gross realized losses	1		—		3

Schedule of Held to Maturity Securities Recognized and Not Recognized in Other Comprehensive Income (OCI) and Fair Values

t December 31, 2015 and 2014, the amortized cost, gross unrealized gains and losses recognized in OCI, carrying amount, gross unrealized gains and losses not recognized in OCI, and fair values of securities held to maturity are presented below.

	December 31, 2015
			Recognized in OCI						Not Recognized in OCI
(Dollars in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Carrying Amount		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Treasury	$	489	$	—	$	—	$	489	$	4	$	—	$	493
U.S. government-sponsored agencies	220		—		—		220		—		4		216
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	7,831		4		53		7,782		49		41		7,790
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,740		—		73		1,667		46		5		1,708
Total securities held to maturity	$	10,280	$	4	$	126	$	10,158	$	99	$	50	$	10,207

	December 31, 2014
			Recognized in OCI						Not Recognized in OCI
(Dollars in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Carrying Amount		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. Treasury	$	486	$	—	$	—	$	486	$	3	$	—	$	489
U.S. government-sponsored agencies	125		—		—		125		—		—		125
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	6,002		6		66		5,942		76		5		6,013
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,820		—		82		1,738		53		6		1,785
Total securities held to maturity	$	8,433	$	6	$	148	$	8,291	$	132	$	11	$	8,412