AOCI (Tables)

12 Months Ended

Dec. 31, 2019

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule of Changes in AOCI

AOCI includes the after-tax change in unrecognized net costs related to defined benefit pension and OPEB plans as well as unrealized gains and losses on cash flow hedges and AFS securities.

(Dollars in millions)	Pension and OPEB Costs		Cash Flow Hedges		AFS Securities		Other, net		Total
AOCI balance, January 1, 2017	$	(764)	$	(92)	$	(259)	$	(17)	$	(1,132)
OCI before reclassifications, net of tax	(129)		7		(23)		5		(140)
Amounts reclassified from AOCI:
Before tax	72		15		(7)		—		80
Tax effect	27		4		(3)		—		28
Amounts reclassified, net of tax	45		11		(4)		—		52
Total OCI, net of tax	(84)		18		(27)		5		(88)
Reclassification of certain tax effects	(156)		(18)		(70)		(3)		(247)
AOCI balance, December 31, 2017	(1,004)		(92)		(356)		(15)		(1,467)
OCI before reclassifications, net of tax	(217)		52		(159)		(6)		(330)
Amounts reclassified from AOCI:
Before tax	75		12		20		1		108
Tax effect	18		3		5		—		26
Amounts reclassified, net of tax	57		9		15		1		82
Total OCI, net of tax	(160)		61		(144)		(5)		(248)
AOCI balance, December 31, 2018	(1,164)		(31)		(500)		(20)		(1,715)
OCI before reclassifications, net of tax	(42)		(89)		790		18		677
Amounts reclassified from AOCI:
Before tax	111		25		119		1		256
Tax effect	27		6		29		—		62
Amounts reclassified, net of tax	84		19		90		1		194
Total OCI, net of tax	42		(70)		880		19		871
AOCI balance, December 31, 2019	$	(1,122)	$	(101)	$	380	$	(1)	$	(844)
Primary income statement location of amounts reclassified from AOCI	Other expense		Net interest income		Net interest income		Net interest income