Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Income Tax Expense

Income tax expense consists of the following:

Year ended December 31,	2021		2020		2019
Current:
Federal	$	39.4	$	42.4	$	40.5
State	11.3		12.3		8.2
Total current	50.7		54.7		48.7
Deferred:
Federal	3.7		(5.7)		3.7
State	1.3		(0.9)		1.7
Total deferred	5.0		(6.6)		5.4
Total income tax expense	$	55.7	$	48.1	$	54.1

Schedule of Effective Income Tax Rate Reconciliation

Total income tax provision differs from the amount of income tax determined by applying the statutory federal income tax rate of 21% for the periods presented to income before income taxes due to the following:

Year ended December 31,	2021		2020		2019
Tax expense at the statutory tax rate	$	52.0	$	44.0	$	49.4
Increase (decrease) in tax resulting from:
Tax-exempt income	(2.8)		(2.1)		(2.8)
State income tax, net of federal income tax benefit	9.9		9.0		9.9
Benefit of stock-based compensation plans	(0.5)		(0.4)		(1.2)
Nondeductible transaction costs	0.8		—		0.2
Federal tax credits	(4.3)		(2.3)		(2.0)
Other, net	0.6		(0.1)		0.6
Tax expense at effective tax rate	$	55.7	$	48.1	$	54.1

Schedule of Deferred Tax Assets and Liabilities

The tax effects of temporary differences between the financial statement carrying amounts and tax bases of assets and liabilities that give rise to significant portions of the net deferred tax asset (liability) relate to the following:

December 31,	2021		2020
Deferred tax assets:
Loans, principally due to allowance for credit losses	$	30.7	$	36.5
Loan discount	1.6		4.0
Investment securities, unrealized losses	4.6		—
Deferred compensation	19.3		19.5
Non-performing loan interest	1.0		1.2
Net operating loss carryforwards (1)	1.7		2.0
Lease liabilities	8.7		9.5
Other	3.5		3.2
Deferred tax assets	71.1		75.9

December 31,	2021		2020
Deferred tax liabilities:
Fixed assets, principally differences in bases and depreciation	(7.7)		(10.9)
Deferred loan costs	(1.9)		(4.4)
Investment securities, unrealized gains	—		(19.2)
Derivatives, unrealized gains	(1.0)		—
Investment in joint venture partnership, principally due to differences in depreciation of partnership assets	(0.9)		(0.9)
Right of use assets	(8.3)		(9.2)
Prepaid amounts	(0.7)		(0.5)
Government agency stock dividends	(1.2)		(1.2)
Goodwill and core deposit intangibles	(51.2)		(50.3)
Mortgage servicing rights	(6.8)		(5.6)
Other	(0.7)		(0.9)
Deferred tax liabilities	(80.4)		(103.1)
Net deferred tax assets (liabilities)	$	(9.3)	$	(27.2)

(1) As of December 31, 2021, we had remaining federal net operating loss carryforwards of $3.1 million from acquired companies, which is available to offset federal taxable income and state net operating loss carryforwards in amounts which vary by state. The federal net operating losses will expire beginning in 2030 and ending in 2036 and the state net operating losses will expire beginning in 2023 and ending in 2034. The use of these carryforwards is subject to annual limitations.