Income taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of Income Tax Expense

The components of income tax expense were as follows:

	Year Ended December 31
	2017		2016		2015
	(In thousands)
Current
Federal	$	363,043	$	428,750	$	130,349
State and local		94,714		95,426		21,549
Total current		457,757		524,176		151,898
Deferred
Federal		367,308		147,662		324,317
State and local		33,482		26,351		72,279
Total deferred		400,790		174,013		396,596
Amortization of investments in qualified affordable housing projects		57,009		45,095		46,531
Total income taxes applicable to pre-tax income	$	915,556	$	743,284	$	595,025

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
	2017			2016			2015
	(In thousands)
Income taxes at statutory federal income tax rate	$	813,352		$	720,439		$	586,142
Increase (decrease) in taxes:
Tax-exempt income		(40,778	)		(35,364	)		(33,102	)
State and local income taxes, net of federal income tax effect		83,327			79,155			60,988
Qualified affordable housing project federal tax credits, net		(16,015	)		(15,091	)		(15,297	)
Initial impact of enactment of Tax Act		85,431			—			—
Other		(9,761	)		(5,855	)		(3,706	)
	$	915,556		$	743,284		$	595,025

Deferred Tax Assets (Liabilities)

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

	2017			2016			2015
	(In thousands)
Losses on loans and other assets	$	345,609		$	590,288		$	637,955
Retirement benefits		45,322			143,067			148,722
Postretirement and other employee benefits		26,009			52,512			55,962
Incentive and other compensation plans		25,050			36,616			60,337
Interest on loans		37,900			61,266			57,640
Stock-based compensation		26,676			52,181			72,090
Unrealized losses		—			10,741			—
Other		66,247			106,876			162,086
Gross deferred tax assets		572,813			1,053,547			1,194,792
Leasing transactions		(181,159	)		(266,268	)		(285,074	)
Unrealized gains		(94,285	)		—			(31,121	)
Capitalized servicing rights		(51,781	)		(71,108	)		(59,171	)
Depreciation and amortization		(52,733	)		(63,959	)		(56,731	)
Other		(21,599	)		(87,200	)		(55,611	)
Gross deferred tax liabilities		(401,557	)		(488,535	)		(487,708	)
Net deferred tax asset	$	171,256		$	565,012		$	707,084

Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

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

	Federal, State and Local Tax			Accrued Interest			Unrecognized Income Tax Benefits
	(In thousands)
Gross unrecognized tax benefits at January 1, 2015	$	10,712		$	3,869		$	14,581
Increases as a result of tax positions taken during 2015		8,108			—			8,108
Increases as a result of tax positions taken in prior years		—			807			807
Decreases as a result of settlements with taxing authorities		(1,515	)		(274	)		(1,789	)
Unrealized tax benefits acquired in a business combination		7,232			3,567			10,799
Gross unrecognized tax benefits at December 31, 2015		24,537			7,969			32,506
Increases as a result of tax positions taken during 2016		12,237			—			12,237
Increases as a result of tax positions taken in prior years		—			656			656
Decreases as a result of tax positions in prior years		(885	)		(710	)		(1,595	)
Gross unrecognized tax benefits at December 31, 2016		35,889			7,915			43,804
Increases as a result of tax positions taken during 2017		13,019			—			13,019
Increases as a result of tax positions taken in prior years		—			1,379			1,379
Decreases as a result of settlements with taxing authorities		(332	)		(168	)		(500	)
Decreases as a result of tax positions taken in prior years		(3,144	)		(3,475	)		(6,619	)
Gross unrecognized tax benefits at December 31, 2017	$	45,432		$	5,651			51,083
Less: Federal, state and local income tax benefits								(10,727	)
Net unrecognized tax benefits at December 31, 2017 that,    if recognized, would impact the effective income tax rate							$	40,356