Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of the provision for income taxes

Significant components of the provision for income taxes are as follows for the periods presented:

	Year Ended December 31,
	2017		2016		2015
Current
Federal	$	28,380	$	31,679	$	17,004
State	1,354		2,131		995
	29,734		33,810		17,999
Deferred
Federal	22,314		10,480		12,625
State	1,147		557		1,126
Revaluation of net deferred tax assets as a result of the Tax Cuts and Jobs Act	14,486		—		—
	37,947		11,037		13,751
	$	67,681	$	44,847	$	31,750

Components of the Company’s investments in qualified affordable housing projects were included in the line item “Income taxes” in the Consolidated Statements of Income for the periods presented as follows:

	Year Ended
	December 31,
	2017			2016
Investment amortization	$	1,714		$	1,335
Tax credits and other benefits	(2,190		)	(1,927		)
Total	$	(476	)	$	(592	)

Reconciliation of income taxes computed at the United States federal statutory tax rates

The reconciliation of income taxes computed at the United States federal statutory tax rates to the provision for income taxes is as follows, for the periods presented:

	Year Ended December 31,
	2017			2016			2015
Tax at U.S. statutory rate	$	55,955		$	47,522		$	34,918
Increase (decrease) in taxes resulting from:
Tax-exempt interest income	(3,595		)	(3,467		)	(3,377		)
BOLI income	(1,524		)	(1,622		)	(1,264		)
Investment tax credits	(1,591		)	(1,390		)	(1,390		)
Amortization of investment in low-income housing tax credits	1,873			1,742			1,734
State income tax expense, net of federal benefit	1,626			1,747			1,378
Revaluation of net deferred tax assets as a result of the Tax Cuts and Jobs Act	14,486			—			—
Other items, net	451			315			(249		)
	$	67,681		$	44,847		$	31,750

Significant components of the Company's deferred tax assets and liabilities

Significant components of the Company’s deferred tax assets and liabilities are as follows for the periods presented:

	December 31,
	2017		2016
Deferred tax assets
Allowance for loan losses	$	13,966	$	19,934
Loans	15,062		23,240
Deferred compensation	7,093		11,254
Net unrealized losses on securities	3,659		10,096
Impairment of assets	1,748		2,512
Net operating loss carryforwards	2,419		2,867
Other	4,722		7,149
Gross deferred tax assets	48,669		77,052
Valuation allowance on state net operating loss carryforwards	—		—
Total deferred tax assets	48,669		77,052
Deferred tax liabilities
Investment in partnerships	757		1,556
Depreciation	3,163		2,517
Mortgage servicing rights	10,139		3,360
Subordinated debt	2,394		4,111
Other	1,859		2,876
Total deferred tax liabilities	18,312		14,420
Net deferred tax assets	$	30,357	$	62,632

Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding

A reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest, related to federal and state income tax matters as of December 31 follows below. These amounts have been adjusted for the change in the tax rate from 35% to 21%.

	2017			2016		2015
Balance at January 1	$	1,510		$	1,485	$	2,653
Additions based on positions related to current period	467			25		367
Additions based on positions related to prior period	—			—		—
Reductions based on positions related to prior period	—			—		(201		)
Settlements	—			—		(1,334		)
Reductions due to lapse of statute of limitations	(371		)	—		—
Balance at December 31	$	1,606		$	1,510	$	1,485