Investment Securities (Tables)

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Investment Securities

 Table 4    Investment Securities

	Available-for-Sale									Held-to-Maturity
At March 31, 2018 (Dollars in Millions)	Amortized Cost		Fair Value		Weighted- Average Maturity in Years		Weighted- Average Yield (e)			Amortized Cost		Fair Value		Weighted- Average Maturity in Years		Weighted- Average Yield (e)
U.S. Treasury and Agencies
Maturing in one year or less	$	4,338	$	4,320		.4		.88	%	$	–	$	–		–		–	%
Maturing after one year through five years		17,042		16,640		3.3		1.66			1,880		1,843		3.3		1.82
Maturing after five years through ten years		1,043		1,006		7.0		2.29			3,273		3,131		5.7		1.79
Maturing after ten years		–		–		–		–			–		–		–		–
Total	$	22,423	$	21,966		2.9		1.54	%	$	5,153	$	4,974		4.8		1.80	%
Mortgage-Backed Securities (a)
Maturing in one year or less	$	110	$	111		.6		4.22	%	$	30	$	30		1.3		2.54	%
Maturing after one year through five years		13,809		13,498		4.5		2.22			18,232		17,747		4.2		2.14
Maturing after five years through ten years		22,800		22,275		6.0		2.35			20,867		20,322		6.1		2.42
Maturing after ten years		2,556		2,566		14.5		2.78			297		298		13.9		2.67
Total	$	39,275	$	38,450		6.0		2.34	%	$	39,426	$	38,397		5.3		2.29	%
Asset-Backed Securities (a)
Maturing in one year or less	$	–	$	–		–		–	%	$	–	$	1		.4		2.48	%
Maturing after one year through five years		408		415		3.7		4.63			4		4		1.7		2.60
Maturing after five years through ten years		–		–		–		–			2		2		4.7		2.56
Maturing after ten years		–		–		–		–			–		2		13.3		2.50
Total	$	408	$	415		3.7		4.63	%	$	6	$	9		2.9		2.58	%
Obligations of State and Political Subdivisions (b) (c)
Maturing in one year or less	$	129	$	131		.4		5.88	%	$	–	$	–		.7		6.33	%
Maturing after one year through five years		661		678		3.2		4.92			1		1		3.9		6.78
Maturing after five years through ten years		3,672		3,667		8.5		4.46			5		6		8.0		2.18
Maturing after ten years		1,918		1,818		19.2		4.11			–		–		–		–
Total	$	6,380	$	6,294		11.0		4.43	%	$	6	$	7		7.4		2.75	%
Other
Maturing in one year or less	$	–	$	–		–		.01	%	$	–	$	–		–		–	%
Maturing after one year through five years		–		–		–		–			21		21		1.0		2.52
Maturing after five years through ten years		–		–		–		–			–		–		–		–
Maturing after ten years		–		–		–		–			–		–		–		–
Total	$	–	$	–		–		.01	%	$	21	$	21		1.0		2.52	%
Total investment securities (d)	$	68,486	$	67,125		5.5		2.29	%	$	44,612	$	43,408		5.2		2.24	%

(a) Information related to asset and mortgage-backed securities included above is presented based upon weighted-average maturities anticipating future prepayments.

(b) Information related to obligations of state and political subdivisions is presented based upon yield to first optional call date if the security is purchased at a premium, yield to maturity if purchased at par or a discount.

(c) Maturity calculations for obligations of state and political subdivisions are based on the first optional call date for securities with a fair value above par and contractual maturity for securities with a fair value equal to or below par.

(d) The weighted-average maturity of the available-for-sale investment securities was 5.1 years at December 31, 2017, with a corresponding weighted-average yield of 2.25 percent. The weighted-average maturity of the held-to-maturity investment securities was 4.7 years at December 31, 2017, with a corresponding weighted-average yield of 2.14 percent.

(e) Weighted-average yields for obligations of state and political subdivisions are presented on a fully-taxable equivalent basis based on a federal income tax rate of 21 percent and 35 percent for the three months ended March 31, 2018 and 2017, respectively. Yields on available-for-sale and held-to-maturity investment securities are computed based on amortized cost balances, excluding any premiums or discounts recorded related to the transfer of investment securities at fair value from available-for-sale to held-to-maturity.

	March 31, 2018					December 31, 2017
(Dollars in Millions)	Amortized Cost		Percent of Total			Amortized Cost		Percent of Total
U.S. Treasury and agencies	$	27,576		24.4	%	$	28,767		25.5	%
Mortgage-backed securities		78,701		69.6			77,606		68.6
Asset-backed securities		414		.4			419		.4
Obligations of state and political subdivisions		6,386		5.6			6,246		5.5
Other		21		–			41		–
Total investment securities	$	113,098		100.0	%	$	113,079		100.0	%

Investment Securities Available-for-Sale

The amortized cost, other-than-temporary impairment recorded in other comprehensive income (loss), gross unrealized holding gains and losses, and fair value of held-to-maturity and available-for-sale investment securities were as follows:

	March 31, 2018											December 31, 2017
					Unrealized Losses											Unrealized Losses
(Dollars in Millions)	Amortized Cost		Unrealized Gains		Other-than- Temporary (a)		Other (b)			Fair Value		Amortized Cost		Unrealized Gains		Other-than- Temporary (a)		Other (b)			Fair Value
Available-for-sale
U.S. Treasury and agencies	$	22,423	$	1	$	–	$	(458	)	$	21,966	$	23,586	$	3	$	–	$	(288	)	$	23,301
Mortgage-backed securities
Residential agency		39,268		143		–		(968	)		38,443		38,450		152		–		(571	)		38,031
Commercial agency		7		–		–		–			7		6		–		–		–			6
Other asset-backed securities		408		7		–		–			415		413		6		–		–			419
Obligations of state and political subdivisions		6,380		51		–		(137	)		6,294		6,240		147		–		(29	)		6,358
Other		–		–		–		–			–		22		–		–		–			22
Total available-for-sale	$	68,486	$	202	$	–	$	(1,563	)	$	67,125	$	68,717	$	308	$	–	$	(888	)	$	68,137

(a) Represents impairment not related to credit for those investment securities that have been determined to be other-than-temporarily impaired.

(b) Represents unrealized losses on investment securities that have not been determined to be other-than-temporarily impaired.

Investment Securities Held-to-Maturity

The amortized cost, other-than-temporary impairment recorded in other comprehensive income (loss), gross unrealized holding gains and losses, and fair value of held-to-maturity and available-for-sale investment securities were as follows:
	March 31, 2018											December 31, 2017
					Unrealized Losses											Unrealized Losses
(Dollars in Millions)	Amortized Cost		Unrealized Gains		Other-than- Temporary (a)		Other (b)			Fair Value		Amortized Cost		Unrealized Gains		Other-than- Temporary (a)		Other (b)			Fair Value
Held-to-maturity
U.S. Treasury and agencies	$	5,153	$	2	$	–	$	(181	)	$	4,974	$	5,181	$	5	$	–	$	(120	)	$	5,066
Residential agency mortgage-backed securities		39,426		37		–		(1,066	)		38,397		39,150		48		–		(579	)		38,619
Asset-backed securities
Collateralized debt obligations/Collateralized loan obligations		–		2		–		–			2		–		4		–		–			4
Other		6		1		–		–			7		6		2		–		–			8
Obligations of state and political subdivisions		6		1		–		–			7		6		1		–		–			7
Obligations of foreign governments		9		–		–		–			9		7		–		–		–			7
Other		12		–		–		–			12		12		–		–		–			12
Total held-to-maturity	$	44,612	$	43	$	–	$	(1,247	)	$	43,408	$	44,362	$	60	$	–	$	(699	)	$	43,723

(a) Represents impairment not related to credit for those investment securities that have been determined to be other-than-temporarily impaired.

(b) Represents unrealized losses on investment securities that have not been determined to be other-than-temporarily impaired.

Amount of Interest Income from Taxable and Non-Taxable Investment Securities

The following table provides information about the amount of interest income from taxable and non-taxable investment securities:

Three Months Ended March 31 (Dollars in Millions)	2018		2017
Taxable	$	561	$	483
Non-taxable		52		47
Total interest income from investment securities	$	613	$	530

Amount of Gross Gains and Losses Realized through Sales of Available-for-Sale Investment Securities

The following table provides information about the amount of gross gains and losses realized through the sales of available-for-sale investment securities:

Three Months Ended March 31 (Dollars in Millions)	2018		2017
Realized gains	$	5	$	47
Realized losses		–		(18	)
Net realized gains (losses)	$	5	$	29
Income tax (benefit) on net realized gains (losses)	$	1	$	11

Gross Unrealized Losses and Fair Value of Company's Investment Securities

The following table shows the gross unrealized losses and fair value of the Company’s investment securities with unrealized losses, aggregated by investment category and length of time the individual investment securities have been in continuous unrealized loss positions, at March 31, 2018:

	Less Than 12 Months					12 Months or Greater					Total
(Dollars in Millions)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Held-to-maturity
U.S. Treasury and agencies	$	2,261	$	(42	)	$	2,557	$	(139	)	$	4,818	$	(181	)
Residential agency mortgage-backed securities		19,957		(448	)		14,298		(618	)		34,255		(1,066	)
Other asset-backed securities		–		–			2		–			2		–
Other		–		–			12		–			12		–
Total held-to-maturity	$	22,218	$	(490	)	$	16,869	$	(757	)	$	39,087	$	(1,247	)
Available-for-sale
U.S. Treasury and agencies	$	13,116	$	(253	)	$	8,747	$	(205	)	$	21,863	$	(458	)
Residential agency mortgage-backed securities		11,235		(236	)		18,977		(732	)		30,212		(968	)
Commercial agency mortgage-backed securities		6		–			–		–			6		–
Obligations of state and political subdivisions		2,437		(46	)		1,249		(91	)		3,686		(137	)
Total available-for-sale	$	26,794	$	(535	)	$	28,973	$	(1,028	)	$	55,767	$	(1,563	)