Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Components of Income Tax Expense (Benefit)

At December 31, income tax expense consisted of the following:



(Dollars in thousands)	2017		2016		2015
Current tax expense
Federal	$	87,992	$	84,946	$	105,367
State	6,116		7,493		16,111
Total current tax expense	94,108		92,439		121,478
Deferred tax expense (benefit)
Federal	115,392		23,144		(2,758		)
State	10,446		10,002		3,308
Total deferred tax expense	125,838		33,146		550
Total income tax expense	$	219,946	$	125,585	$	122,028

Schedule of Effective Income Tax Rate Reconciliation

Income tax expense differed from the amounts computed by applying the federal income tax rate of 35 percent to pretax income as a result of the following:



(Dollars in thousands)	2017			2016			2015
Income taxes at federal statutory rates	$	190,294		$	122,874		$	116,345
Increase (reduction) in income taxes resulting from:
Nontaxable income on loans, leases and investments, net of nondeductible expenses	(2,525		)	(2,901		)	(3,020		)
State and local income taxes, including change in valuation allowance, net of federal income tax benefit	10,765			11,372			12,622
Effect of federal rate change	25,762			—			—
Acquisition stock settlement	—			(98		)	—
Tax credits net of amortization	(4,840		)	(4,138		)	(3,060		)
Other, net	490			(1,524		)	(859		)
Total income tax expense	$	219,946		$	125,585		$	122,028

Schedule of Deferred Tax Assets and Liabilities

The net deferred tax asset included the following components at December 31:



(Dollars in thousands)	2017		2016
Allowance for loan and lease losses	$	50,853	$	80,939
Pension liability	704		15,679
Executive separation from service agreements	8,548		14,278
Federal net operating loss carryforward	2,685		5,019
Net unrealized loss on securities included in accumulated other comprehensive loss	10,849		26,832
Accelerated depreciation	—		133
FDIC assisted transactions timing differences	—		52,579
Other reserves	5,570		10,504
Other	10,116		26,663
Deferred tax asset	89,325		232,626
Accelerated depreciation	7,562		—
Lease financing activities	9,131		11,651
Net deferred loan fees and costs	8,708		10,867
Intangible assets	12,252		6,335
Security, loan and debt valuations	7,018		22,656
FDIC assisted transactions timing differences	1,113		—
Other	4,565		8,501
Deferred tax liability	50,349		60,010
Net deferred tax asset	$	38,976	$	172,616

Schedule of Unrecognized Tax Benefits

The following table provides a rollforward of Bancshares’ gross unrecognized tax benefits, excluding interest and penalties, during the years ended December 31:



(Dollars in thousands)	2017		2016			2015
Unrecognized tax benefits at the beginning of the year	$	28,879	$	5,975		$	3,865
Reductions related to tax positions taken in prior year	—		(327		)	(79		)
Additions related to tax positions taken in current year	125		23,231			2,189
Unrecognized tax benefits at the end of the year	$	29,004	$	28,879		$	5,975