Income Taxes (Tables)

3 Months Ended

Mar. 31, 2019

Income Tax Disclosure [Abstract]

Summary of Differences in Taxes from Continuing Operations Computed at Statutory Rate

Following is a summary of the major items comprising the differences in taxes from continuing operations computed at the federal statutory rate and as recorded in the consolidated statements of income:

	Three Months Ended
	March 31,
(dollars in thousands)		2019				2018
Provision at statutory rate of 21%	$	14,570			$	11,117
Tax-exempt income:
Tax-exempt interest		(2,531	)			(2,191	)
Section 291/265 interest disallowance		111				62
Company-owned life insurance income		(669	)			(547	)
Tax-exempt income		(3,089	)			(2,676	)
State income taxes		1,999				1,188
Interim period effective rate adjustment		688				92
Tax credit investments - federal		(420	)			(5,769	)
Other, net		(644	)			1,005
Income tax expense	$	13,104			$	4,957
Effective tax rate		18.9		%		9.4		%

Schedule of Significant Components of Net Deferred Tax Assets (Liabilities)

Significant components of net deferred tax assets (liabilities) were as follows at March 31, 2019 and December 31, 2018:

	March 31,			December 31,
(dollars in thousands)	2019			2018
Deferred Tax Assets
Allowance for loan losses, net of recapture	$	14,458		$	14,514
Benefit plan accruals		14,624			21,754
Alternative minimum tax credit		2,545			2,545
Net operating loss carryforwards		30,168			31,765
Federal tax credits		3,116			1,779
Deferred gain on securities		1,844			1,976
Acquired loans		24,857			26,956
Operating lease liabilities		30,451			—
Lease exit obligation		—			1,025
Unrealized losses on available-for-sale investment securities		—			11,853
Unrealized losses on held-to-maturity investment securities		2,391			2,497
Tax credit investments and other partnerships		3,196			3,004
Other real estate owned		144			144
Other, net		2,691			3,167
Total deferred tax assets		130,485			122,979
Deferred Tax Liabilities
Accretion on investment securities		(795	)		(595	)
Purchase accounting		(17,873	)		(18,100	)
Loan servicing rights		(6,080	)		(6,141	)
Premises and equipment		(11,019	)		(8,507	)
Prepaid expenses		(716	)		(681	)
Operating lease right-of-use assets		(29,393	)		—
Unrealized gains on available-for-sale investment securities		(2,725	)		—
Unrealized gains on hedges		(167	)		(358	)
Other, net		(2,287	)		(1,549	)
Total deferred tax liabilities		(71,055	)		(35,931	)
Net deferred tax assets	$	59,430		$	87,048