Securities

9 Months Ended

Sep. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Securities

Securities

In conjunction with the adoption of new accounting standards, an immaterial amount of HTM securities was transferred to AFS securities and an immaterial amount of equity securities was transferred from AFS securities to other assets in the first quarter of 2018. The following tables summarize AFS and HTM securities:

September 30, 2018 (Dollars in millions)	Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses
AFS securities:
U.S. Treasury	$	2,505	$	—	$	127	$	2,378
GSE	210		—		12		198
Agency MBS	21,582		3		1,213		20,372
States and political subdivisions	764		24		17		771
Non-agency MBS	335		194		—		529
Other	37		1		—		38
Total AFS securities	$	25,433	$	222	$	1,369	$	24,286
HTM securities:
U.S. Treasury	$	1,099	$	—	$	15	$	1,084
GSE	2,199		—		71		2,128
Agency MBS	17,775		31		764		17,042
States and political subdivisions	8		—		—		8
Other	1		—		—		1
Total HTM securities	$	21,082	$	31	$	850	$	20,263
December 31, 2017 (Dollars in millions)	Amortized Cost		Gross Unrealized				Fair Value
			Gains		Losses
AFS securities:
U.S. Treasury	$	2,368	$	—	$	77	$	2,291
GSE	187		—		8		179
Agency MBS	20,683		8		590		20,101
States and political subdivisions	1,379		37		24		1,392
Non-agency MBS	384		192		—		576
Other	8		—		—		8
Total AFS securities	$	25,009	$	237	$	699	$	24,547
HTM securities:
U.S. Treasury	$	1,098	$	8	$	—	$	1,106
GSE	2,198		11		22		2,187
Agency MBS	19,660		33		222		19,471
States and political subdivisions	28		—		—		28
Other	43		2		—		45
Total HTM securities	$	23,027	$	54	$	244	$	22,837

Certain securities issued by FNMA and FHLMC exceeded 10% of shareholders' equity at September 30, 2018. The FNMA investments had total amortized cost and fair value of $13.6 billion and $12.9 billion, respectively. The FHLMC investments had total amortized cost and fair value of $9.9 billion and $9.4 billion, respectively.

The amortized cost and estimated fair value of the securities portfolio by contractual maturity are shown in the following table. The expected life of MBS may differ from contractual maturities because borrowers have the right to prepay the underlying mortgage loans.

	AFS				HTM
September 30, 2018 (Dollars in millions)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	481	$	479	$	1	$	1
Due after one year through five years	2,114		1,991		3,190		3,109
Due after five years through ten years	561		547		687		660
Due after ten years	22,277		21,269		17,204		16,493
Total debt securities	$	25,433	$	24,286	$	21,082	$	20,263

The following tables present the fair values and gross unrealized losses of investments based on the length of time that individual securities have been in a continuous unrealized loss position:

	Less than 12 months				12 months or more				Total
September 30, 2018 (Dollars in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
AFS securities:
U.S. Treasury	$	452	$	8	$	1,926	$	119	$	2,378	$	127
GSE	33		1		165		11		198		12
Agency MBS	4,052		111		15,949		1,102		20,001		1,213
States and political subdivisions	146		1		272		16		418		17
Total	$	4,683	$	121	$	18,312	$	1,248	$	22,995	$	1,369
HTM securities:
U.S. Treasury	$	1,084	$	15	$	—	$	—	$	1,084	$	15
GSE	900		24		1,081		47		1,981		71
Agency MBS	6,869		266		8,549		498		15,418		764
Total	$	8,853	$	305	$	9,630	$	545	$	18,483	$	850
	Less than 12 months				12 months or more				Total
December 31, 2017 (Dollars in millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
AFS securities:
U.S. Treasury	$	634	$	4	$	1,655	$	73	$	2,289	$	77
GSE	9		—		170		8		179		8
Agency MBS	5,077		64		13,920		526		18,997		590
States and political subdivisions	201		1		355		23		556		24
Total	$	5,921	$	69	$	16,100	$	630	$	22,021	$	699
HTM securities:
GSE	$	1,470	$	12	$	290	$	10	$	1,760	$	22
Agency MBS	10,880		77		4,631		145		15,511		222
Total	$	12,350	$	89	$	4,921	$	155	$	17,271	$	244

Substantially all of the unrealized losses on the securities portfolio were the result of changes in market interest rates compared to the date the securities were acquired rather than the credit quality of the issuers or underlying loans.