Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Taxes

Schedule of provision for income taxes

	Year Ended December 31,
(Dollars in thousands)	2017		2016		2015
Current:
Federal	$	46,153	$	37,187	$	41,527
State		3,018		3,325		2,327
Total current tax expense		49,171		40,512		43,854
Deferred:
Federal		31,971		11,684		6,344
State		109		564		704
Total deferred tax expense		32,080		12,248		7,048
Provision for income taxes	$	81,251	$	52,760	$	50,902

Analysis of difference between the provision for income taxes and taxes computed by applying the federal statutory income tax rate to income before provision for income taxes

	Year Ended December 31,
(Dollars in thousands)	2017		2016		2015
Income taxes at federal statutory rate	$	59,082	$	53,915	$	52,631
Increase (reduction) of taxes resulting from:
State income taxes, net of federal tax benefit		2,032		2,527		1,970
Non-deductible merger expenses		586		686		—
Tax-exempt interest		(2,840)		(1,956)		(1,842)
Income tax credits		(1,951)		(2,068)		(1,781)
Dividends received deduction		(12)		(12)		(8)
Revaluation of net deferred tax asset due to tax law change		26,558		—		—
Other, net		(2,204)		(332)		(68)
	$	81,251	$	52,760	$	50,902

Schedule of components of the net deferred tax asset

	December 31,
(Dollars in thousands)	2017		2016
Allowance for loan losses	$	11,011	$	14,913
Other-than-temporary impairment on securities		257		295
Share-based compensation		3,935		3,915
Pension plan and post-retirement benefits		607		1,450
Deferred compensation		13,048		3,155
Purchase accounting adjustments		33,888		34,499
FDIC Acquisition		3,190		—
Other real estate owned		838		962
Tax deductible goodwill		32		682
Net operating loss carryforwards		14,066		14,645
Cash flow hedge		54		190
Unrealized losses on investment securities available for sale		3,472		1,053
Other		643		688
Total deferred tax assets		85,041		76,447
FDIC Acquisition		—		3,540
Depreciation		5,870		7,510
Intangible assets		14,745		11,239
Deferred loan fees		7,840		7,911
Prepaid expense		474		523
Mortgage servicing rights		6,818		10,380
Other		372		2,219
Total deferred tax liabilities		36,119		43,322
Net deferred tax assets before valuation allowance		48,922		33,125
Less, valuation allowance		(3,020)		(2,002)
Net deferred tax assets	$	45,902	$	31,123