Federal and State Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Summary of consolidated income tax expense

The following table is a summary of consolidated income tax expense:

	Years ended
(Dollars in thousands)	December 31, 2016			December 31, 2015		December 31, 2014
Current
Federal	$	30,461		28,705		21,860
State	9,283			9,374		8,118
Total current income tax expense	39,744			38,079		29,978
Deferred 1
Federal	(70		)	(3,451	)	5,016
State	(12		)	(629	)	915
Total deferred income tax (benefit) expense	(82		)	(4,080	)	5,931
Total income tax expense	$	39,662		33,999		35,909

__________

¹  Includes tax benefit of operating loss carryforwards of $571,000, $391,000 and $0 for the years ended December 31, 2016, 2015, and 2014, respectively.

Summary of effective tax rate

Combined federal and state income tax expense differs from that computed at the federal statutory corporate tax rate as follows:

	Years ended
	December 31, 2016		December 31, 2015		December 31, 2014
Federal statutory rate	35.0	%	35.0	%	35.0	%
State taxes, net of federal income tax benefit	3.8	%	3.7	%	4.0	%
Tax-exempt interest income	(12.2	)%	(12.6	)%	(11.5	)%
Tax credits	(2.1	)%	(3.0	)%	(2.8	)%
Other, net	0.2	%	(0.5	)%	(0.5	)%
Effective tax rate	24.7	%	22.6	%	24.2	%

Summary of net deferred tax asset

The tax effect of temporary differences which give rise to a significant portion of deferred tax assets and deferred tax liabilities are as follows:

(Dollars in thousands)	December 31, 2016			December 31, 2015
Deferred tax assets
Allowance for loan and lease losses	$	50,172		50,123
Deferred compensation	8,320			8,166
Other real estate owned	8,309			8,380
Interest rate swap agreements	5,705			7,554
Acquisition fair market value adjustments	4,763			5,842
Net operating loss carryforwards	4,737			3,590
Employee benefits	3,927			3,165
Other	5,569			5,433
Total gross deferred tax assets	91,502			92,253
Deferred tax liabilities
Deferred loan costs	(8,061		)	(7,427	)
Intangibles	(5,477		)	(6,272	)
FHLB stock dividends	(3,976		)	(4,601	)
Depreciation of premises and equipment	(3,111		)	(2,376	)
Available-for-sale securities	(1,036		)	(8,812	)
Other	(2,720		)	(4,290	)
Total gross deferred tax liabilities	(24,381		)	(33,778	)
Net deferred tax asset	$	67,121		58,475

Income tax return jurisdictions and years subject to examination

The following schedule summarizes the years that remain subject to examination as of December 31, 2016:

	Years ended December 31,
Federal	2013, 2014 and 2015
Montana	2013, 2014 and 2015
Idaho	2013, 2014 and 2015
Colorado	2012, 2013, 2014 and 2015
Utah	2013, 2014 and 2015