Income taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Components of Income Tax Expense

The components of income tax expense were as follows:

	Year Ended December 31,
(Dollars in millions)	2023			2022			2021
Current:
Federal	$	580		$	367		$	332
State and local		228			143			85
Total current		808			510			417
Deferred:
Federal		(64	)		(18	)		72
State and local		(33	)		(12	)		15
Total deferred		(97	)		(30	)		87
Amortization of investments in qualified affordable housing projects		167			140			92
Total income taxes applicable to pre-tax income	$	878		$	620		$	596

Schedule of Income Tax Expense Benefit Reconciliation

Total income taxes differed from the amount computed by applying the statutory federal income tax rate to pre-tax income as follows:

	Year Ended December 31,
(Dollars in millions)	2023			2022			2021
Income taxes at statutory federal income tax rate	$	760		$	548		$	516
Increase (decrease) in taxes:
Tax-exempt income		(51	)		(37	)		(21	)
State and local income taxes, net of federal income tax effect		161			110			101
Qualified affordable housing project tax benefits, net		(26	)		(22	)		(15	)
Other		34			21			15
	$	878		$	620		$	596

Deferred Tax Assets (Liabilities)

Deferred tax assets (liabilities) were comprised of the following at December 31:

(Dollars in millions)	2023			2022			2021
Losses on loans and other assets	$	686		$	641		$	396
Operating lease liabilities		182			183			110
Postretirement and other employee benefits		47			—			32
Incentive and other compensation plans		30			34			25
Unrealized losses		64			115			—
Interest on loans		42			54			—
Losses on cash flow hedges		52			87			—
Stock-based compensation		54			51			33
Other		153			81			52
Gross deferred tax assets		1,310			1,246			648
Right-of-use assets and other leasing transactions		(336	)		(367	)		(249	)
Unrealized gains		—			—			(27	)
Retirement benefits		(198	)		(88	)		(46	)
Capitalized servicing rights		(38	)		(51	)		(53	)
Postretirement and other employee benefits		—			(29	)		—
Depreciation and amortization		(157	)		(155	)		(93	)
Interest on loans		—			—			(7	)
Gains on cash flow hedges		—			—			(23	)
Other		(59	)		(69	)		(88	)
Gross deferred tax liabilities		(788	)		(759	)		(586	)
Net deferred tax asset	$	522		$	487		$	62

Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits follows:

(Dollars in millions)	Federal, State and Local Tax			Accrued Interest			Unrecognized Income Tax Benefits
Gross unrecognized tax benefits at January 1, 2021	$	49		$	8		$	56
Increases as a result of tax positions taken in prior years		—			3			3
Decreases as a result of tax positions taken in prior years		(11	)		(3	)		(14	)
Gross unrecognized tax benefits at December 31, 2021		38			8			45
Increases as a result of tax positions taken in prior years		—			3			3
Unrecognized tax benefits assumed in a business combination		3			1			5
Decreases as a result of tax positions taken in prior years		(11	)		(4	)		(15	)
Gross unrecognized tax benefits at December 31, 2022		30			8			38
Increases as a result of tax positions taken in prior years		5			1			6
Decreases as a result of tax positions taken in prior years		(13	)		(3	)		(16	)
Gross unrecognized tax benefits at December 31, 2023	$	22		$	6		$	28
Less: Federal, state and local income tax benefits								(6	)
Net unrecognized tax benefits at December 31, 2023 that,    if recognized, would impact the effective income tax rate							$	22