Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of Income Tax Expense

The current and deferred components of income tax expense on the consolidated statements of income were as follows:

	For The Year Ended December 31,
	2017			2016			2015
Current:
Federal	$	14,529		$	17,854		$	7,956
State	1,289			930			71
	15,818			18,784			8,027
Deferred:
Change in federal corporate income tax rate(1)	14,263			—			—
Federal	4,117			(1,258		)	1,356
State	(320		)	(54		)	524
	18,060			(1,312		)	1,880
Income tax expense	$	33,878		$	17,472		$	9,907

Reconciliation of Expected Income Tax Benefit Computed Using Federal Statutory Income Tax Rate

The income tax expense differs from the amount computed by applying the statutory federal income tax rate as a result of the following:

	For The Year Ended December 31,
	2017			2016			2015
Computed tax expense	$	21,824		$	20,139		$	10,801
Increase (reduction) in income taxes resulting from:
Change in federal corporate income tax rate	14,263			—			—
Tax exempt income	(1,291		)	(1,312		)	(1,092		)
Income from life insurance	(829		)	(908		)	(588		)
State taxes, net of federal benefit	630			565			373
Share-based awards(1)	(390		)	(701		)	—
Low income housing credits	(366		)	(376		)	(359		)
Non-deductible acquisition-related costs	—			—			467
Other	37			65			305
Income tax expense	$	33,878		$	17,472		$	9,907
Income before income taxes	$	62,354		$	57,539		$	30,859
Effective tax rate	54.3		%	30.4		%	32.1		%

Schedule of Deferred Tax Assets and Deferred Tax Liabilities

Temporary differences between the financial statements carrying amounts and the tax bases of assets and liabilities gave rise to the following deferred tax assets and liabilities:

	December 31,
	2017(1)					2016(2)
	Asset		Liability			Asset		Liability
Net operating loss and tax credit carryforward	$	12,078	$	—		$	20,977	$	—
Allowance for loan losses	5,201		—			8,094		—
Pension and other benefits	3,363		—			5,141		—
Net unrealized losses on AFS securities	2,821		—			3,227		—
Net unrealized losses on derivative instruments	1,623		—			3,066		—
Deferred compensation and benefits	1,199		—			1,791		—
Net unrealized losses on postretirement plans	1,092		—			1,147		—
Purchase accounting and deposit premium	461		—			1,430		—
Depreciation	—		(2,857		)	—		(4,520		)
Deferred loan origination fees	—		(1,510		)	—		(2,046		)
Other	—		(695		)	956		—
	27,838		(5,062		)	45,829		(6,566		)
Valuation allowance on deferred tax assets			—					—
Net deferred tax assets			$	22,776				$	39,263