First Interstate BancSystem (FIBK) 10-Q 5 Aug 22 2022 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2022	Jul. 31, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-34653
Entity Registrant Name	FIRST INTERSTATE BANCSYSTEM, INC.
Entity Incorporation, State or Country Code	MT
Entity Tax Identification Number	81-0331430
Entity Address, Address Line One	401 North 31st Street
Entity Address, City or Town	Billings,
Entity Address, State or Province	MT
Entity Address, Postal Zip Code	59116-0918
City Area Code	406
Local Phone Number	255-5311
Title of 12(b) Security	Class A common stock, no par value
Trading Symbol	FIBK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		106,820,008
Amendment Flag	false
Entity Central Index Key	0000860413
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Assets
Cash and due from banks	$ 425.3	$ 168.6
Interest bearing deposits in banks	633.9	2,176.1
Federal funds sold	0.1	0.1
Total cash and cash equivalents	1,059.3	2,344.8
Securities Purchased under Agreements to Resell	202.2	0
Investment securities:
Available-for-sale, at estimated fair value	7,741.1	4,820.5
Held-to-maturity, net of allowance for credit losses of $1.6 and $0 at June 30, 2022 and December 31, 2021 (estimated fair values of $2,860.5 and $1,667.5 at June 30, 2022 and December 31, 2021)	3,130	1,687.6
Total investment securities	10,871.1	6,508.1
Loans held for sale	127.4	30.1
Loans held for investment, net of deferred fees and costs	17,162.5	9,331.7
Allowance for credit losses	220.4	122.3
Net loans held for investment	16,942.1	9,209.4
Goodwill	1,099.8	621.6
Bank Owned Life Insurance	492.8	301.5
Premises and equipment, net of accumulated depreciation	442.7	299.6
Other intangibles, net of accumulated amortization	105.1	41.3
Accrued interest receivable	90.6	47.4
Mortgage servicing rights, net of accumulated amortization and impairment reserve	32.1	28.2
Other real estate owned	16.8	2
Deferred tax assets	176.9	0
Other assets	402.9	237.9
Total assets	32,061.8	19,671.9
Deposits:
Non-interest bearing	8,295.4	5,568.3
Interest bearing	18,568.4	10,701.3
Total deposits	26,863.8	16,269.6
Securities sold under repurchase agreements	1,234.7	1,051.1
Accounts payable and accrued expenses	397.5	148.4
Accrued interest payable	4.3	3.7
Deferred tax liability, net	0	9.3
Long-term debt	120.4	112.4
Allowance for credit losses on off-balance sheet credit exposures	6.1	3.8
Subordinated debentures held by subsidiary trusts	163.1	87
Total liabilities	28,789.9	17,685.3
Stockholders’ equity:
Preferred stock, no par value; 100,000 shares authorized; none issued and outstanding	0	0
Common stock, no par value; 150,000,000 and 100,000,000 shares authorized at June 30, 2022 and December 31, 2021; 107,758,038 shares and 62,200,456 shares issued and outstanding, respectively	2,607.9	945
Retained earnings	993.8	1,052.6
Accumulated other comprehensive loss, net	(329.8)	(11)
Total stockholders’ equity	3,271.9	1,986.6
Total liabilities and stockholders’ equity	$ 32,061.8	$ 19,671.9

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Investment securities:
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 1,600,000	$ 0
Estimated fair value	$ 2,860,500,000	$ 1,667,500,000
Stockholders' equity:
Preferred Stock, Par or Stated Value Per Share	$ 0	$ 0
Nonvoting, noncumulative preferred stock, shares authorized (in shares)	100,000	100,000
Nonvoting, noncumulative preferred stock, shares issued (in shares)	0	0
Nonvoting, noncumulative preferred stock, shares outstanding (in shares)	0	0
Preferred Stock, Shares Outstanding	0	0
Shares outstanding (in shares)	107,758,038	62,200,456
Common Stock, Shares, Issued	107,758,038	62,200,456
Common Stock, Shares Authorized	150,000,000	100,000,000
Common Stock, Par or Stated Value Per Share	$ 0	$ 0
Class A Common Stock
Stockholders' equity:
Shares outstanding (in shares)		41,699,409

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Interest income:
Interest and fees on loans	$ 191.7	$ 105.4	$ 343.4	$ 213.2
Interest and dividends on investment securities:
Taxable	48.8	15.8	78.1	31.6
Exempt from federal taxes	1.4	1.4	2.7	2.8
Interest on deposits in banks	3.4	0.7	5.1	1
Total interest income	245.3	123.3	429.3	248.6
Interest expense:
Interest on deposits	4.3	2.2	7.3	4.5
Interest on securities sold under repurchase agreements	0.3	0.1	0.6	0.2
Interest on long-term debt	1.4	1.5	3.1	3
Interest on subordinated debentures held by subsidiary trusts	1.4	0.7	2.4	1.4
Total interest expense	7.4	4.5	13.4	9.1
Net interest income	237.9	118.8	415.9	239.5
Provision for (reversal of) credit losses	(1.7)	0	59.6	(5.1)
Net interest income after provision for (reversal of) credit losses	239.6	118.8	356.3	244.6
Non-interest income:
Debt Securities, Available-for-sale, Gain (Loss)	(0.1)	(0.1)	(0.2)	(0.1)
Mortgage banking revenues	5	9.6	13.4	21.2
Other income	7.4	2.6	13.4	6.7
Total non-interest income	51	35.3	100.2	73.4
Non-interest expense:
Salaries and wages	74.8	41.6	134.8	80.6
Employee benefits	19.4	14.7	40.6	30.8
Outsourced technology services	12.8	8.4	24.1	16.5
Occupancy, net	11.2	7.1	21.2	14.4
Furniture and equipment	5.8	4.1	11.2	8.5
OREO expense, net of income	0	0	0.1	(0.1)
Professional fees	5.5	3.2	9.4	6.6
FDIC insurance premiums	2.8	1.5	6.1	3.1
Other intangibles amortization	4.1	2.5	7.7	5
Other expenses	28.1	15.9	51.3	32
Acquisition related expenses	45.8	0	111	0
Noninterest Expense	210.3	99	417.5	197.4
Income before income tax	80.3	55.1	39	120.6
Provision for income tax	16.2	12.6	8.3	26.7
Net income	$ 64.1	$ 42.5	$ 30.7	$ 93.9
Earnings per common share, basic (in dollars per share)	$ 0.59	$ 0.69	$ 0.30	$ 1.52
Earnings per common share, diluted (in dollars per share)	$ 0.59	$ 0.69	$ 0.30	$ 1.52
Weighted average common shares outstanding, basic (in shares)	109,106,891	61,657,593	101,025,926	61,624,917
Weighted average common shares outstanding, diluted (in shares)	109,131,718	61,727,821	101,076,331	61,723,142
Payment services revenues
Non-interest income:
Non-interest income	$ 19.5	$ 11.4	$ 34.3	$ 21.6
Wealth management revenues
Non-interest income:
Wealth management revenues	9.3	6.3	17.4	12.6
Service charges on deposit accounts
Non-interest income:
Non-interest income	6.3	3.9	14	7.7
Other service charges, commissions, and fees
Non-interest income:
Non-interest income	$ 3.6	$ 1.6	$ 7.9	$ 3.7

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 64.1	$ 42.5	$ 30.7	$ 93.9
Other comprehensive (loss) income, before tax:
Change in net unrealized loss during period	(161.6)	(0.8)	(414.2)	(67.6)
Reclassification adjustment for net loss included in income	0.1	0.1	0.2	0.1
Reclassification adjustment for securities transferred from held-to-maturity to available-for-sale	0	0	0.2	0
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax	(0.9)	24.8	(23.9)	24.8
Change in unrealized (gain) loss on derivatives	(15)	(0.8)	6.3	(0.9)
Other comprehensive (loss) income, before tax	(177.4)	23.3	(431.4)	(43.6)
Changes in deferred taxes related to other comprehensive (loss) income	49.6	(5.9)	112.6	11.1
Other comprehensive (loss) income, net of tax	(127.8)	17.4	(318.8)	(32.5)
Comprehensive (loss) income, net of tax	$ (63.7)	$ 59.9	$ (288.1)	$ 61.4

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Common stock	Retained earnings	Accumulated other comprehensive income (loss)
Equity, beginning balance at Dec. 31, 2020	$ 1,959.8	$ 941.1	$ 962.1	$ 56.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	93.9	0	93.9	0
Other comprehensive income (loss), net of tax expense	(32.5)	0	0	(32.5)
Common stock transactions:
Common shares purchased and retired	(5.4)	(5.4)	0	0
Common shares issued	0	0	0	0
Non-vested common shares issued	0	0	0	0
Non-vested common shares forfeited or canceled	0	0	0	0
Stock options exercised, net of share tendered in payment of option price and income tax withholding amounts	0.4	0.4	0	0
Stock-based compensation expense	5.5	5.5	0	0
Common cash dividend declared	(50.8)	0	(50.8)	0
Equity, ending balance at Jun. 30, 2021	1,970.9	941.6	1,005.2	24.1
Equity, beginning balance at Mar. 31, 2021	1,933.4	938.5	988.2	6.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	42.5	0	42.5	0
Other comprehensive income (loss), net of tax expense	17.4	0	0	17.4
Common stock transactions:
Common shares purchased and retired	0	0	0	0
Common shares issued	0	0	0	0
Non-vested common shares issued	0	0	0	0
Stock options exercised, net of share tendered in payment of option price and income tax withholding amounts	3.1	3.1	0	0
Stock-based compensation expense	(25.5)	0	(25.5)	0
Equity, ending balance at Jun. 30, 2021	1,970.9	941.6	1,005.2	24.1
Equity, beginning balance at Dec. 31, 2021	1,986.6	945	1,052.6	(11)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30.7	0	30.7	0
Other comprehensive income (loss), net of tax expense	(318.8)	0	0	(318.8)
Common stock transactions:
Common shares purchased and retired	(65.9)	(65.9)	0	0
Common shares issued	1,722.5	1,722.5	0	0
Non-vested common shares issued	0	0	0	0
Non-vested common shares forfeited or canceled	0	0	0	0
Stock options exercised, net of share tendered in payment of option price and income tax withholding amounts	0.1	0.1	0	0
Stock-based compensation expense	6.2	6.2	0	0
Common cash dividend declared	(89.5)	0	(89.5)	0
Equity, ending balance at Jun. 30, 2022	3,271.9	2,607.9	993.8	(329.8)
Equity, beginning balance at Mar. 31, 2022	3,441.1	2,668.6	974.5	(202)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	64.1	0	64.1	0
Other comprehensive income (loss), net of tax expense	(127.8)	0	0	(127.8)
Common stock transactions:
Common shares purchased and retired	(64.5)	(64.5)	0	0
Common shares issued	0	0	0	0
Non-vested common shares issued	0	0	0	0
Non-vested common shares forfeited or canceled	0	0	0	0
Stock-based compensation expense	3.8	3.8	0	0
Common cash dividend declared	(44.8)	0	(44.8)	0
Equity, ending balance at Jun. 30, 2022	$ 3,271.9	$ 2,607.9	$ 993.8	$ (329.8)

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Stockholders' Equity [Abstract]
Stock repurchased and retired (in shares)	1,722,044	284	1,759,742	127,464
Common shares issued (in shares)	26,266	18,477	46,913,370	19,081
Non-vested common shares issued (in shares)	2,626		453,439	239,525
Non-vested common shares forfeited (in shares)	51,820	8,305	67,292	27,373
stock options exercised (in shares)			17,807	40,663
Shares tendered (in shares)			4,877	6,177
Common dividends (in dollars per share)	$ 0.41	$ 0.41	$ 0.82	$ 0.82

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income	$ 30.7	$ 93.9
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for (reversal of) credit losses	59.6	(5.1)
Net gain on disposal of premises and equipment	(1.4)	(0.4)
Depreciation and amortization	27.5	22.3
Net premium amortization on investment securities	13.5	18.3
Net loss on investment securities transactions	0.2	0.1
Realized and unrealized net gains on mortgage banking activities	(7.6)	(10.7)
Net gain on sale of OREO	(0.1)	(0.2)
Gain (Loss) on Extinguishment of Debt	(1.4)	0
Mortgage servicing rights recovery	(3.4)	(5.9)
Deferred taxes	(8.8)	9
Net increase in cash surrender value of company-owned life insurance	(4.7)	(2.6)
Stock-based compensation expense	6.2	5.5
Originations of mortgage loans held for sale	(241.2)	(359.3)
Proceeds from sales of mortgage loans held for sale	263.1	394.3
Changes in operating assets and liabilities:
(Increase) decrease in interest receivable	(10.1)	0.2
Decrease (increase) in other assets	7.6	(39.3)
Decrease in accrued interest payable	(1.8)	(0.8)
Increase (decrease) in accounts payable and accrued expenses	141.3	(13.2)
Net cash provided by operating activities	269.2	106.1
Purchases of investment securities:
Held-to-maturity	(848.2)	(1,022.1)
Available-for-sale	(2,521.2)	(1,219.9)
Proceeds from sales, maturities, and pay-downs of investment securities:
Held-to-maturity	193.4	55.4
Available-for-sale	1,057.8	542.5
Extensions of credit to clients, net of repayments	(39.2)	(37)
Recoveries of loans charged-off	0	(5.7)
Proceeds from sale of OREO	1.2	1
Proceeds from the sale of Health Savings Accounts	1.4	0
Acquisition of bank and bank holding company, net of cash and cash equivalents received	2,006.9	0
Payments for (Proceeds from) Productive Assets	(15.5)	(0.3)
Net cash used in investing activities	(163.4)	(1,674.7)
Cash flows from financing activities:
Net (decrease) increase in deposits	(1,093.8)	1,348.7
Net increase (decrease) in securities sold under repurchase agreements	8.5	(52.7)
Repayments of long-term debt	(157.9)	0
Advances on long-term debt	8	0
Payments of Stock Issuance Costs	(0.8)	0
Proceeds from issuance of common stock, net	0.1	0.4
Purchase and retirement of common stock	(65.9)	(5.4)
Dividends paid to common stockholders	(89.5)	(50.8)
Net cash (used in) provided by financing activities	(1,391.3)	1,240.2
Net decrease in cash and cash equivalents	(1,285.5)	(328.4)
Cash and cash equivalents at beginning of period	2,344.8	2,276.8
Cash and cash equivalents at end of period	1,059.3	1,948.4
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	13.8	35.7
Cash paid during the period for interest expense	13.5	9.8
Supplemental disclosures of non-cash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	19.9	0.4
Net change in unamortized (losses) gains on available-for-sale securities transferred into held-to-maturity	10.9	0
Debt Securities, Available-For-Sale, Transfer, Unrealized Gain (Loss)	463.6	672.2
Transfer of loans from held-for-sale to held for investment	19.8	0
Transfer of loans to other real estate owned	0.1	0.3
Asset Acquisition, Consideration Transferred, Equity Interest Issued and Issuable	1,723.3	0
Capitalization of internally originated mortgage servicing rights	1.6	0.9
Investment securities	2,699	0
Securities Purchased under Agreements to Resell, Increase	101.1	0
Loans held for sale	217	0
Loans held for investment, net	7,645.5	0
Premises and equipment	144.9	0
Goodwill	478.2	0
Company-owned life insurance	186.6	0
Noncash or Part Noncash Acquisition, Deferred Tax Assets Acquired	63.6	0
Noncash or Part Noncash Acquisition, Intangible Assets Acquired, Other Real Estate Owned	15.8	0
Other assets	198	0
Total noncash assets acquired	11,823.9	0
Noncash or Part Noncash Acquisition, Liabilities Assumed, Deposits	11,688	0
Securities sold under repurchase agreements	74	0
Accounts payable and accrued expenses	110.1	0
Long-term debt	159.3	0
Noncash or Part Noncash Acquisition, Liabilities Assumed, Trust preferred securities	76.1	0
Total liabilities assumed	12,107.5	0
Core Deposits
Supplemental disclosures of non-cash investing and financing activities:
Other intangibles	72.9	0
Servicing Contracts
Supplemental disclosures of non-cash investing and financing activities:
Other intangibles	$ 1.3	$ 0

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	In the opinion of management, the accompanying unaudited consolidated financial statements of First Interstate BancSystem, Inc., First Interstate Bank (“FIB”), and its other subsidiaries (collectively, the “Company”) contain all adjustments (all of which are of a normal recurring nature) necessary to present fairly the financial position of the Company at June 30, 2022 and December 31, 2021, the results of operations, changes in stockholders’ equity, and cash flows for each of the three and the six month periods ended June 30, 2022 and 2021, in conformity with U.S. generally accepted accounting principles (“GAAP”). The balance sheet information at December 31, 2021 is derived from the audited consolidated financial statements. Certain reclassifications, none of which were material, have been made to conform the Company’s prior year financial statements to the June 30, 2022 presentation. These reclassifications did not change previously reported net income or stockholders’ equity. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, which includes a description of significant accounting policies. Operating results for the three and the six months ended June 30, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2022
Business Combinations [Abstract]
Acquisitions	Acquisition Great Western Bank. On September 15, 2021, the Company entered into a definitive agreement (“Agreement”) to acquire 100% of the outstanding stock of Great Western Bancorp, Inc. (“Great Western”), the parent company of Great Western Bank (“GWB”), a Sioux Falls, South Dakota based community bank with 174 banking offices across Arizona, Colorado, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota. The acquisition of GWB expanded the Company’s geographical footprint with an enhanced platform for future growth. The acquisition was completed on February 1, 2022. Consideration for the acquisition was $1,723.3 million, consisting of the issuance of 46.9 million shares of the Company’s Class A common stock valued at $36.76 per share, which was the opening price of the Company’s Class A common stock as quoted on the NASDAQ stock market on the acquisition date. Holders of shares of Great Western common stock received 0.8425 shares of First Interstate Class A common stock for each whole share of Great Western common stock and received cash in lieu of fractional shares. Previously unvested Great Western restricted stock awards that were outstanding immediately prior to the close of the transaction became vested and were considered issued and outstanding at acquisition close and included in consideration. The Company accounted for this transaction under the acquisition method of accounting in accordance with ASC 805, Business Combinations , which requires purchased assets and liabilities assumed and consideration exchanged to be recorded at their respective estimated fair values at the date of acquisition. The determination of estimated fair values required management to make certain estimates about discount rates, future expected cash flows, and market conditions at the time of the acquisition, as well as other future events that are highly subjective in nature. This determination is subject to refinement for up to one year after the closing date of the acquisition as additional information relative to the closing date fair values becomes available and such information is considered final, whichever is earlier. The following table provides the provisional purchase price allocation as of the acquisition date and the Great Western assets acquired and liabilities assumed at their estimated fair value as of the acquisition date as amended for measurement period adjustments as of June 30, 2022. We recorded the estimate of fair value based on initial valuations available at the acquisition date. The excess value of the consideration paid over the fair value of assets acquired and liabilities assumed was recorded as goodwill. The purchase price allocation resulted in provisional goodwill of $478.2 million, which is not deductible for income tax purposes. Goodwill resulting from the acquisition was allocated to the Company’s one operating segment, community banking, and consists largely of the synergies and economies of scale expected from combining the operations of Great Western and the Company. Due to the recent closing of the transaction, all amounts reported are provisional pending the review of valuations obtained from third parties and other necessary information in support of related fair value accounting. As of February 1, 2022 Assets acquired: Cash and cash equivalents $ 2,006.9 Investment securities 2,699.0 Securities purchased under agreement to resell 101.1 Loans held for sale 217.0 Loans held for investment 7,705.0 Allowance for credit losses (59.5) Premises and equipment, including right of use lease assets 144.9 Other real estate owned (“OREO”) 15.8 Company owned life insurance 186.6 Core deposit intangibles 50.1 Customer relationship intangible 22.8 Mortgage servicing rights 1.3 Deferred tax assets, net 63.6 Other assets 198.0 Total assets acquired 13,352.6 Liabilities assumed: Deposits 11,688.0 Securities sold under repurchase agreements 74.0 Accrued expenses and other liabilities 110.1 FHLB advances 122.9 Subordinated debt 36.4 Subordinated debentures held by subsidiary trusts 76.1 Total liabilities assumed 12,107.5 Net assets acquired $ 1,245.1 Consideration paid: Class A common stock 1,723.3 Total consideration paid (1) $ 1,723.3 Goodwill $ 478.2 (1) Includes $13 thousand of cash paid in lieu of fractional shares. As of June 30, 2022, the Company recorded measurement period adjustments to the fair value marks as indicated in the table below. These adjustments resulted in a net decrease to goodwill of $37.8 million from the March 31, 2022 reported balances. The related impact to net income that would have been recognized in previous periods if the adjustments were recognized as of the acquisition date was not material to the consolidated financial statements. Asset adjustments: Loans held for sale $ 35.1 Loans held for investment (8.4) Allowance for credit losses 24.8 Premises and equipment 0.8 Core deposit intangibles 1.0 Deferred tax assets (12.5) Total asset adjustments $ 40.8 Liability adjustments: Accrued expenses and other liabilities $ 3.0 Total liability adjustments $ 3.0 Net adjustment to goodwill $ (37.8) The Company determined the fair value of loans, core deposit and customer relationship intangible assets, investment securities, premises and equipment, leases, mortgage servicing rights, deposits, FHLB advances, subordinated debt, and subordinated debentures held by subsidiary trusts with the assistance of third-party valuation specialists. The following is a description of the methods used to determine the fair values of significant assets and liabilities presented above. Cash and cash equivalents The carrying amount of these assets is a reasonable estimate of fair value based on the short-term nature of these assets. Investment Securities Fair values for securities are based on quoted market prices, where available. If quoted market prices are not available, fair value estimates are based on observable inputs including quoted market prices for similar instruments, quoted market prices that are not in an active market or other inputs that are observable in the market. In the absence of observable inputs, fair value is estimated based on pricing models and/or discounted cash flow methodologies. Loans held for sale The loans held for sale portfolio was recorded at fair value based on quotes or bids from third party investors. Loans held for investment A valuation of the loans held for investment portfolio was performed by a third party as of the acquisition date in accordance with ASC 820 to assess the fair value of the loan portfolio, considering adjustments for interest rate risk, required equity return, servicing, credit, and liquidity risk. The loans held for investment portfolio was segmented into two groups including purchase credit deteriorated (PCD) loans and non-PCD loans. The non-PCD loans were pooled based on similar characteristics, such as loan type, fixed or adjustable interest rates, payment type, index rate and caps/floors, and non-accrual status. The PCD loans were valued at the loan level with similar characteristics noted above. The fair value was calculated using a discounted cash flow analysis. The discount rate utilized to analyze fair value considered the cost of funds rate, capital charge, servicing costs, and liquidity premium, mostly based on industry standards. The Company is required to record PCD assets, defined as a more-than-insignificant deterioration in credit quality since origination or issuance, at the purchase price plus the allowance for credit losses expected at the time of acquisition. Under this method, there is no credit loss expense affecting net income on acquisition of PCD assets. Changes in estimates of expected credit losses after acquisition are recognized in subsequent periods as credit loss expense (or reversal of credit loss expense) arise. Any non-credit discount or premium resulting from acquiring a pool of purchased financial assets with credit deterioration is allocated to each individual asset. At the acquisition date, the initial allowance for credit losses determined on a collective basis is allocated to individual assets to appropriately allocate any non-credit discount or premium. The non-credit discount or premium, after the adjustment for the allowance for credit losses, is accreted to interest income using the interest method based on the effective interest rate determined after the adjustment for credit losses at the adoption date. Information regarding loans acquired at the acquisition date as amended for measurement period adjustments as of June 30, 2022 were as follows: (In millions) PCD loans: Unpaid principal balance $ 979.2 Principal amounts previously written off by GWB (238.7) Interest applied to principal by GWB (18.1) Adjusted unpaid principal balance 722.4 Credit discount (69.2) Discount attributable to other factors (29.9) Fair value 623.3 Allowance for credit losses 59.5 Amortized cost basis 682.8 Non-PCD loans: Unpaid principal balance 7,107.9 Credit discount (1) (76.5) Non-credit discount (9.2) Fair value 7,022.2 Amortized cost basis $ 7,705.0 (1) Represents the best estimate of the contractual cash flows not expected to be collected as of the acquisition date. Core deposit intangible Core deposit intangible assets of $50.1 million on non-maturing deposits were determined by evaluating the underlying characteristics of the deposit relationships, including customer attrition, deposit interest rates and maintenance costs, and costs of alternative funding using the discounted cash flow approach. The core deposit intangibles represent the costs saved by the Company between maintaining the existing deposits and obtaining alternative funds over the life of the deposit base. These costs are amortized using an accelerated method over the estimated useful life of 10 years for the related deposits. Premises and equipment The fair values of premises are based on a market approach, using third-party appraisals and other analysis of value for land and premises. Deposits The fair values used for the demand and savings deposits equal the amounts payable on demand at the acquisition date. In determining the fair value of certificates of deposit, the cash flows of the contractual interest payments during the specific period of the certificates of deposit and scheduled principal payout were discounted to present value at market-based interest rates. Customer relationship intangible Customer relationship intangible assets of $22.8 million were determined using an excess earnings model associated with the expected fee income related to the underlying client relationships and is being amortized using the straight-line method over the estimated useful life of 12 years. FHLB advances The fair value of fixed rate Federal Home Loan Bank of Des Moines (“FHLB”) advances was determined using a discounted cash flow approach. The cash flows of the advances were projected based on scheduled payments of the fixed rate advances, which factored in prepayment fees. The cash flows were then discounted to present value using the FHLB rates as of February 1, 2022. Subordinated debt and subordinated debentures held by subsidiary trusts The fair value of subordinated debt and subordinated debentures held by subsidiary trusts was determined by using a discounted cash flow method using a market participant discount rate for similar instruments over the remaining terms. Acquisition related expenses related to the GWB acquisition of $45.8 million and $111.0 million for the three and the six month periods ended June 30, 2022, respectively, were included as a component of non-interest expense in the consolidated statements of income, of which approximately $1.0 million and $26.8 million for the three and the six month periods ended June 30, 2022, respectively, are acquisition related costs as defined by ASC 805. During the six months ended June 30, 2022, the Company contributed $21.5 million to the First Interstate Foundation and reimbursed an aggregate of $8.2 million of the Scott family control group’s acquisition expenses pursuant to the Agreement. The accompanying consolidated statements of income for the three and the six months ended June 30, 2022, include the results of operations of the acquired entity from the February 1, 2022 acquisition date. The disclosure of GWB post-acquisition revenue and net income is not practical due to the combining of certain GWB operations with and into FIB as of the acquisition date. GWB was merged with our existing bank subsidiary, First Interstate Bank, contemporaneously with the closing of the parent company merger. The core system conversion was completed on May 23, 2022. The following table presents certain unaudited pro forma financial information for illustrative purposes only, for the three and the six month periods ended June 30, 2022 and 2021 as if GWB had been acquired on January 1, 2021. This unaudited pro forma information combines the historical results of GWB with the Company’s consolidated historical results and includes certain adjustments reflecting the estimated impact of certain fair value adjustments for the respective periods. The pro forma information is not indicative of what would have occurred had the acquisition occurred at the beginning of the year prior to the acquisition. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value, cost savings, or business synergies. As a result, actual amounts would have differed from the unaudited pro forma information presented, and the differences could be significant. Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Total revenues $ 300.7 $ 291.8 $ 569.6 $ 613.4 Net income $ 101.1 $ 144.6 $ 177.5 $ 66.4 Earnings per common share (Basic) $ 0.93 $ 1.33 $ 1.76 $ 0.61 Earnings per common share (Diluted) $ 0.93 $ 1.33 $ 1.76 $ 0.61

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangibles	6 Months Ended
	Jun. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill Management analyzes its goodwill for impairment on an annual basis and between annual tests in certain circumstances, such as upon material adverse changes in legal, business, regulatory, and economic factors. An impairment loss is recorded to the extent that the carrying amount of goodwill exceeds its implied fair value. The Company performed an impairment assessment as of July 1, 2021 and 2020 and concluded that there was no impairment to goodwill. The following table details changes in the recorded amount of goodwill as of the dates indicated: As of June 30, June 30, 2022 December 31, 2021 Net carrying value at beginning of the period $ 621.6 $ 621.6 Provisional additions to goodwill from acquisition 478.2 — Net carrying value at end of period $ 1,099.8 $ 621.6 Other Intangible Assets Other intangible assets are comprised of core deposit intangibles (“CDI”) and other customer relationship intangibles (“OCRI”) and amounted to the following at June 30, 2022 and December 31, 2021: As of June 30, 2022 CDI OCRI Total Gross other intangible assets, at beginning of the period $ 106.0 $ — $ 106.0 Provisional amounts established through acquisition 50.1 22.8 72.9 Reductions due to sale of health savings accounts (1.4) — (1.4) Accumulated amortization (71.6) (0.8) (72.4) Net other intangible assets, end of period $ 83.1 $ 22.0 $ 105.1 December 31, 2021 Gross other intangible assets, at beginning of the period $ 106.0 $ — $ 106.0 Accumulated amortization (64.7) — (64.7) Net other intangible assets, end of period $ 41.3 $ — $ 41.3 The Company recorded $4.1 million and $2.5 million of other intangible asset amortization expense for the three months ended June 30, 2022 and 2021, respectively, and recorded $7.7 million and $5.0 million of other intangible asset amortization expense for the six months ended June 30, 2022 and 2021, respectively CDI and OCRI are evaluated for impairment if events and circumstances indicate a possible impairment. CDI is amortized using an accelerated method based on the estimated weighted average useful lives of the related deposits, which is generally 10 years. OCRI is amortized using a straight-line method over its estimated useful life of 12 years based on customer revenue attrition on an annualized basis. The following table provides the estimated aggregate future amortization expense of other intangible assets: Years Ending December 31, CDI OCRI Total 2022 remaining $ 7.2 $ 0.9 $ 8.1 2023 13.7 1.9 15.6 2024 12.7 1.9 14.6 2025 11.8 1.9 13.7 2026 10.9 1.9 12.8 Thereafter 26.8 13.5 40.3 Total $ 83.1 $ 22.0 $ 105.1

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Investment Securities	The amortized cost and the approximate fair values of investment securities are summarized as follows: June 30, 2022 Amortized Gross Gross Estimated Available-for-Sale: U.S. Treasury notes $ 871.0 $ 1.4 $ (62.6) $ 809.8 State, county, and municipal securities 325.0 0.1 (42.9) 282.2 Obligations of U.S. government agencies 235.3 — (9.4) 225.9 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 5,054.7 2.0 (241.3) 4,815.4 Private mortgage-backed securities 278.1 — (25.1) 253.0 Collateralized loan obligations 1,145.7 — (51.7) 1,094.0 Corporate securities 284.0 — (23.2) 260.8 Total $ 8,193.8 $ 3.5 $ (456.2) $ 7,741.1 June 30, 2022 Amortized Allowance for Credit Losses Net Carrying Amount Gross Gross Estimated Held-to-Maturity: U.S. Treasury notes $ 296.7 $ — $ 296.7 $ — $ (3.6) $ 293.1 State, county, and municipal securities 186.6 (0.1) 186.5 0.5 (24.0) 163.0 Obligations of U.S. government agencies 328.1 — 328.1 — (28.9) 299.2 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations (1) 2,236.0 — 2,236.0 — (208.7) 2,027.3 Corporate securities 84.2 (1.5) 82.7 — (4.8) 77.9 Total $ 3,131.6 $ (1.6) $ 3,130.0 $ 0.5 $ (270.0) $ 2,860.5 (1) Amortized cost presented above include $21.1 million of unamortized losses and $15.9 million of unamortized gains in U.S. agency residential and commercial mortgage-backed securities and collateralized mortgage obligations related to the 2021 and 2022 transfer of securities from available-for-sale to held-to-maturity. December 31, 2021 Amortized Gross Gross Estimated Available-for-Sale: U.S. Treasury notes $ 697.6 $ — $ (12.9) $ 684.7 State, county, and municipal securities 434.7 2.1 (9.3) 427.5 Obligations of U.S. government agencies 356.0 0.1 (9.2) 346.9 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 2,027.3 14.1 (23.3) 2,018.1 Private mortgage-backed securities 174.4 0.1 (1.1) 173.4 Collateralized loan obligation 898.2 1.2 — 899.4 Corporate securities 271.1 3.0 (3.6) 270.5 Total $ 4,859.3 $ 20.6 $ (59.4) $ 4,820.5 December 31, 2021 Amortized Allowance for Credit Losses Net Carrying Amount Gross Gross Estimated Held-to-Maturity: State, county, and municipal securities $ 67.6 $ — $ 67.6 $ 2.0 $ (0.4) $ 69.2 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations (1) 1,609.0 — 1,609.0 13.2 (35.3) 1,586.9 Corporate securities 11.0 — 11.0 0.4 — 11.4 Total $ 1,687.6 $ — $ 1,687.6 $ 15.6 $ (35.7) $ 1,667.5 (1) Amortized cost presented above include $20.1 million of unamortized gains in U.S. agency residential and commercial mortgage-backed securities and collateralized mortgage obligations related to the 2021 transfer of securities from available-for-sale to held-to-maturity. On February 1, 2022, in conjunction with the acquisition of GWB and under ASC 320, the Company transferred debt securities classified as held-to-maturity with an amortized cost of $10.7 million and an estimated fair value of $10.9 million to the available-for-sale category classification and transferred debt securities classified as available-for-sale with an amortized cost of $485.9 million and an estimated fair value of $463.6 million to the held-to-maturity classification to maintain the Company’s intended risk profile. The transfer of debt securities into the available-for-sale and held-to-maturity categories were recorded at fair value on the date of transfer. This discount, as well as the related unrealized loss in accumulated other comprehensive income, will be amortized into interest income as a yield adjustment over the remaining term of the securities. The amortization of the unrealized loss reported in accumulated other comprehensive (loss) income will offset the effect on interest income of the accretion of the discount. No gains or losses were recorded at the time of transfer. The following tables show the gross unrealized losses and fair values of investment securities, aggregated by investment category, and the length of time individual investment securities have been in an unrealized loss position as of June 30, 2022 and December 31, 2021. Less than 12 Months 12 Months or More Total June 30, 2022 Fair Gross Fair Gross Fair Gross Available-for-Sale: U.S. Treasury notes $ 177.6 $ (23.0) $ 458.1 $ (39.6) $ 635.7 $ (62.6) State, county, and municipal securities 136.7 (15.8) 123.3 (27.1) 260.0 (42.9) Obligations of U.S. government agencies 191.7 (6.5) 28.1 (2.9) 219.8 (9.4) U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 3,838.2 (159.7) 621.8 (81.6) 4,460.0 (241.3) Private mortgage-backed securities 242.9 (24.2) 10.1 (0.9) 253.0 (25.1) Collateralized loan obligations 1,094.0 (51.7) — — 1,094.0 (51.7) Corporate securities 149.4 (6.2) 90.5 (17.0) 239.9 (23.2) Total $ 5,830.5 $ (287.1) $ 1,331.9 $ (169.1) $ 7,162.4 $ (456.2) Less than 12 Months 12 Months or More Total December 31, 2021 Fair Gross Fair Gross Fair Gross Available-for-Sale: U.S. Treasury notes $ 684.7 $ (12.9) $ — $ — $ 684.7 $ (12.9) State, county, and municipal securities 278.7 (9.1) 5.0 (0.2) 283.7 (9.3) Obligations of U.S. government agencies 297.0 (8.9) 16.4 (0.3) 313.4 (9.2) U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 1,262.8 (23.0) 26.4 (0.3) 1,289.2 (23.3) Private mortgage-backed securities 127.2 (1.1) — — 127.2 (1.1) Corporate securities 109.9 (3.3) 20.9 (0.3) 130.8 (3.6) Total $ 2,760.3 $ (58.3) $ 68.7 $ (1.1) $ 2,829.0 $ (59.4) As of June 30, 2022 and December 31, 2021, there were no holdings of securities of any issuer, other than the U.S. government and its agencies, in an amount greater than 10% of stockholders’ equity. During the six months ended June 30, 2022, the Company acquired $2,356.9 million of available-for-sale securities and $342.1 million of held-to-maturity securities in connection with the acquisition of GWB. Such securities were evaluated and it was determined that there were no investment securities that met the definition of a PCD asset and none were classified as PCD upon acquisition. The Company determines credit losses on both available-for-sale and held-to-maturity investment securities by a discounted cash flow approach using the security’s effective interest rate at the time of purchase or upon acquisition. The allowance for credit losses is measured as the amount by which an investment security’s amortized cost exceeds the net present value of expected future cash flows. However, the amount of credit losses for available-for-sale investment securities is limited to the amount of a security’s unrealized loss. Credit losses on held-to-maturity investment securities are representative of current expected credit losses that may be incurred over the life of the investment. The allowance for credit losses is established through a charge to provision for credit losses in current period earnings. The available-for-sale securities portfolio contains securities that are guaranteed by a sovereign entity or are generally considered to have non-credit related risks, such as interest rate risk or prepayment and liquidity factors. The Company considers whether the securities are issued by the federal government or its agencies and whether downgrades by bond rating agencies have occurred. The Company had no allowance for credit losses for available-for-sale investment securities as of June 30, 2022 and December 31, 2021. As of June 30, 2022 and December 31, 2021, the Company had 1,155 and 285 individual investment securities, respectively, that were in an unrealized loss position, which was related primarily to fluctuations in current interest rates. As of June 30, 2022, the Company had the intent and ability to hold these investment securities for a period of time sufficient to allow for an anticipated recovery. The Company does not intend to sell any of the available-for-sale securities in the above table and the Company does not anticipate it will have to sell any securities before a recovery in cost. The following table presents the activity in the allowance for credit losses related to held-to-maturity securities classified as corporate and state, county, and municipal securities: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 1.6 $ — $ — $ — Provision for credit loss expense — — 1.6 — Ending balance of allowance for credit losses $ 1.6 $ — $ 1.6 $ — There was no allowance for credit losses on held-to-maturity securities at December 31, 2021. On a quarterly basis, the Company refreshes the credit quality of each held-to-maturity security. The following table summarizes the credit quality indicators of held-to-maturity securities at amortized cost for the periods indicated: June 30, 2022 AAA AA A BBB Not Rated Total U.S. Treasury notes $ 296.7 $ — $ — $ — $ — $ 296.7 State, county, and municipal securities 69.4 95.1 12.0 — 10.1 186.6 Obligations of U.S. government agencies 328.1 — — — — 328.1 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations FNMA/FHLMC 1,903.2 — — — — 1,903.2 GNMA 332.8 — — — — 332.8 Corporate securities — — 4.0 75.2 5.0 84.2 Total $ 2,930.2 $ 95.1 $ 16.0 $ 75.2 $ 15.1 $ 3,131.6 December 31, 2021 AAA AA A BBB Not Rated Total State, county, and municipal securities $ 17.2 $ 31.6 $ 14.7 $ — $ 4.1 $ 67.6 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations FNMA/FHLMC 1,439.1 — — — — 1,439.1 GNMA 169.9 — — — — 169.9 Corporate securities — — 4.0 7.0 — 11.0 Total $ 1,626.2 $ 31.6 $ 18.7 $ 7.0 $ 4.1 $ 1,687.6 As of June 30, 2022 and December 31, 2021, the Company had $30.8 million and $16.6 million, respectively, of accrued interest receivable on the consolidated balance sheet. The Company does not consider accrued interest receivable in the carrying amount of financial assets held at the amortized cost basis or in the allowance for credit losses calculation. As of June 30, 2022 and December 31, 2021, there were no available-for-sale or held-to-maturity securities on nonaccrual status. All securities in the portfolio were current with their contractual principal and interest payments. As of June 30, 2022 and December 31, 2021, there were no collateral dependent available-for-sale or held-to-maturity securities. There were no material gross realized gains and no material gross realized losses on the disposition of available-for-sale investment securities during the three and the six month periods ended June 30, 2022 and 2021. Maturities of securities do not reflect rate repricing opportunities present in adjustable-rate mortgage-backed securities. Maturities of mortgage-backed securities have been adjusted to reflect shorter maturities based upon estimated prepayments of principal. All other investment securities maturities are shown at contractual maturity dates. Available-for-Sale Held-to-Maturity June 30, 2022 Amortized Estimated Amortized Estimated Within one year $ 84.8 $ 84.4 $ 10.1 $ 10.1 After one year but within five years 1,566.4 1,507.7 375.0 367.9 After five years but within ten years 1,865.4 1,738.6 784.5 718.4 After ten years 4,677.2 4,410.4 1,962.0 1,764.1 Total $ 8,193.8 $ 7,741.1 $ 3,131.6 $ 2,860.5 As of June 30, 2022, the Company held investment securities callable within one year having amortized costs and estimated fair values of $813.9 million and $775.9 million, respectively. These investment securities are primarily included in the “after five years but within ten years” category in the table above. As of June 30, 2022, the Company had no callable structured notes. As of June 30, 2022 and December 31, 2021, the Company has amortized costs of $4,871.3 million and $2,617.8 million, respectively, for investment securities pledged to secure public deposits and securities sold under repurchase agreements and had approximate fair values of $4,526.5 million and $2,610.8 million, as of June 30, 2022 and December 31, 2021, respectively. All securities sold under repurchase agreements are with clients and mature on the next banking day. The Company retains possession of the underlying securities sold under repurchase agreements.

Loans Held for Sale

Loans Held for Sale	6 Months Ended
	Jun. 30, 2022
Loans Held for Sale [Abstract]
Loans Held for Sale	The following table presents loans held for sale by segment for the dates indicated: June 30, December 31, Loans Held for Sale: Agricultural $ 113.3 $ — Residential real estate 14.1 30.1 Total loans held for sale $ 127.4 $ 30.1 Residential real estate loans that the Company originated with the intent to sell are recorded at fair value. Conforming agency mortgage production is sold on a servicing retained basis. Certain loans, such as government guaranteed mortgage loans, are sold on a servicing released basis. The fair value of loans held for sale are primarily determined based on quoted prices for similar loans in active markets or outstanding commitments from third-party investors. Net unrealized losses, if any, are recorded as a valuation allowance and charged to non-interest income in the consolidated statements from operations. Net gains and losses on loan sales are recorded as a component of non-interest income. As of June 30, 2022, loans held for sale included nonaccrual loans of $37.2 million, all of which were agricultural loans. There were no loans held for sale that were considered a troubled debt restructuring as of June 30, 2022. On February 1, 2022, in conjunction with the acquisition of GWB, agricultural loans with a carrying value of $155.8 million and commercial loans with a carrying value of $24.0 million were reclassified as loans held for sale from loans held for investment due to management’s intent and decision to sell the loans. During the first quarter of 2022, agricultural loans with a carrying value of $19.8 million were reclassified from loans held for sale to loans held for investment due to management’s change in intent and decision not to sell the loans. On the date of transfer, the amortized cost exceeded the fair value of the loans due to credit deterioration. The Company recorded a charge-off of $5.1 million to the allowance for credit losses, which established a new aggregate cost basis for the loans of $14.7 million on the date of transfer. In addition to the reclassification, the Company recorded net repayments and discounted pay-offs of $4.5 million.

Loans Held for Investment

Loans Held for Investment	6 Months Ended
	Jun. 30, 2022
Receivables [Abstract]
Loans	Loans Held for Investment The following table presents loans by segment as of the dates indicated: June 30, December 31, Real estate loans: Commercial $ 7,857.7 $ 3,971.5 Construction loans: Land acquisition & development 355.7 247.8 Residential 444.8 262.0 Commercial 959.0 498.0 Total construction loans 1,759.5 1,007.8 Residential 2,060.4 1,538.2 Agricultural 821.5 213.9 Total real estate loans 12,499.1 6,731.4 Consumer loans: Indirect 733.9 737.6 Direct and advance lines 157.3 129.2 Credit card 74.8 64.9 Total consumer loans 966.0 931.7 Commercial 3,036.0 1,475.5 Agricultural 672.0 203.9 Other, including overdrafts — 1.5 Loans held for investment 17,173.1 9,344.0 Deferred loan fees and costs (10.6) (12.3) Loans held for investment, net of deferred fees and costs 17,162.5 9,331.7 Allowance for credit losses (220.4) (122.3) Net loans held for investment $ 16,942.1 $ 9,209.4 Allowance for Credit Losses The following tables represent, by loan portfolio segment, the activity in the allowance for credit losses for loans held for investment: Three Months Ended June 30, 2022 Beginning Balance Provisional ACL Recorded for PCD loans Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 45.2 $ (6.9) $ (8.8) $ — $ — $ 29.5 Owner occupied 25.2 — 1.4 — — 26.6 Multi-family 54.6 (19.0) (2.9) — 0.7 33.4 Total commercial real estate 125.0 (25.9) (10.3) — 0.7 89.5 Construction: Land acquisition & development 0.5 — 0.2 — 0.1 0.8 Residential construction 3.3 — 0.1 — — 3.4 Commercial construction 10.2 — 4.7 — — 14.9 Total construction 14.0 — 5.0 — 0.1 19.1 Residential real estate: Residential 1-4 family 18.7 — (0.7) — 0.2 18.2 Home equity and HELOC 1.4 — (0.1) — 0.2 1.5 Total residential real estate 20.1 — (0.8) — 0.4 19.7 Agricultural real estate 10.5 — (5.1) (0.1) 0.1 5.4 Total real estate 169.6 (25.9) (11.2) (0.1) 1.3 133.7 Consumer: Indirect 13.5 — (0.4) (0.8) 0.8 13.1 Direct and advance lines 4.6 — 0.5 (0.6) 0.5 5.0 Credit card 2.3 — 0.7 (0.9) 0.1 2.2 Total consumer 20.4 — 0.8 (2.3) 1.4 20.3 Commercial: Commercial and floor plans 52.9 — 1.9 (1.1) 0.4 54.1 Commercial purpose secured by 1-4 family 5.0 — 0.4 — 0.1 5.5 Credit card 0.3 — 0.1 (0.1) — 0.3 Total commercial 58.2 — 2.4 (1.2) 0.5 59.9 Agricultural: Agricultural (2) (1.0) 1.1 6.3 (0.1) 0.2 6.5 Total agricultural (1.0) 1.1 6.3 (0.1) 0.2 6.5 Total allowance for credit losses $ 247.2 $ (24.8) $ (1.7) $ (3.7) $ 3.4 $ 220.4 (1) Amounts presented exclude the allowance for credit losses related to unfunded commitments. These amounts are included in Note “Financial Instruments with Off-Balance Sheet Risk” and the allowance for credit losses related to investment securities which are included in Note “Investment Securities” included in this report. (2) The agricultural ACL beginning balance reflects loan reclassifications to conform the March 31, 2022 loan classifications to June 30, 2022 which were offset by additional provisional ACL as of June 30, 2022. Six Months Ended June 30, 2022 Beginning Balance Provisional ACL Recorded for PCD loans Provision for (reversal of) Credit Losses (2) Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 17.3 $ 17.2 $ (2.1) $ (2.9) $ — $ 29.5 Owner occupied 13.3 9.5 6.0 (2.2) — 26.6 Multi-family 13.3 10.9 8.5 — 0.7 33.4 Total commercial real estate 43.9 37.6 12.4 (5.1) 0.7 89.5 Construction: Land acquisition & development 0.5 3.4 (0.6) (2.7) 0.2 0.8 Residential construction 2.4 — 1.0 — — 3.4 Commercial construction 6.0 0.2 8.7 — — 14.9 Total construction 8.9 3.6 9.1 (2.7) 0.2 19.1 Residential real estate: Residential 1-4 family 13.4 0.1 4.5 (0.1) 0.3 18.2 Home equity and HELOC 1.2 — — — 0.3 1.5 Total residential real estate 14.6 0.1 4.5 (0.1) 0.6 19.7 Agricultural real estate 1.9 2.3 1.3 (0.2) 0.1 5.4 Total real estate 69.3 43.6 27.3 (8.1) 1.6 133.7 Consumer: Indirect 14.3 — (0.7) (1.7) 1.2 13.1 Direct and advance lines 4.6 — 0.4 (1.4) 1.4 5.0 Credit card 2.2 — 1.3 (1.5) 0.2 2.2 Total consumer 21.1 — 1.0 (4.6) 2.8 20.3 Commercial: Commercial and floor plans 27.1 11.2 20.3 (5.3) 0.8 54.1 Commercial purpose secured by 1-4 family 4.4 0.2 0.8 — 0.1 5.5 Credit card 0.1 — 0.4 (0.2) — 0.3 Total commercial 31.6 11.4 21.5 (5.5) 0.9 59.9 Agricultural: Agricultural 0.3 4.5 5.8 (5.4) 1.3 6.5 Total agricultural 0.3 4.5 5.8 (5.4) 1.3 6.5 Total allowance for credit losses $ 122.3 $ 59.5 $ 55.6 $ (23.6) $ 6.6 $ 220.4 (1) Amounts presented are exclusive of the allowance for credit losses related to unfunded commitments which are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report. (2) Amounts include $68.3 million related to the acquired GWB non-PCD loans. Three Months Ended June 30, 2021 Beginning Balance Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 23.0 $ (0.2) $ — $ 0.1 $ 22.9 Owner occupied 17.4 1.4 (2.2) — 16.6 Multi-family 11.8 (0.2) — — 11.6 Total commercial real estate 52.2 1.0 (2.2) 0.1 51.1 Construction: Land acquisition & development 1.2 (0.4) (0.1) 0.3 1.0 Residential construction 1.4 0.2 (0.1) — 1.5 Commercial construction 7.2 0.9 (0.1) — 8.0 Total construction 9.8 0.7 (0.3) 0.3 10.5 Residential real estate: Residential 1-4 family 11.5 1.9 — — 13.4 Home equity and HELOC 1.4 (0.1) — 0.1 1.4 Total residential real estate 12.9 1.8 — 0.1 14.8 Agricultural real estate 2.8 0.2 — — 3.0 Total real estate 77.7 3.7 (2.5) 0.5 79.4 Consumer: Indirect 16.0 (0.2) (0.8) 0.8 15.8 Direct and advance lines 4.8 — (0.4) 0.2 4.6 Credit card 1.5 0.3 (0.4) 0.2 1.6 Total consumer 22.3 0.1 (1.6) 1.2 22.0 Commercial: Commercial and floor plans 31.0 (3.4) (0.3) 1.7 29.0 Commercial purpose secured by 1-4 family 4.7 (0.4) (0.1) 0.2 4.4 Credit card 0.3 — (0.1) 0.1 0.3 Total commercial 36.0 (3.8) (0.5) 2.0 33.7 Agricultural: Agricultural 0.6 — (0.2) — 0.4 Total agricultural 0.6 — (0.2) — 0.4 Total allowance for credit losses $ 136.6 $ — $ (4.8) $ 3.7 $ 135.5 (1) Amounts presented exclude the allowance for credit losses related to unfunded commitments. These amounts are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report. Six Months Ended June 30, 2021 Beginning Balance Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 25.5 $ (2.7) $ — $ 0.1 $ 22.9 Owner occupied 18.3 0.6 (2.3) — 16.6 Multi-family 11.0 0.6 — — 11.6 Total commercial real estate 54.8 (1.5) (2.3) 0.1 51.1 Construction: Land acquisition & development 1.3 (0.6) (0.1) 0.4 1.0 Residential construction 1.6 — (0.1) — 1.5 Commercial construction 7.3 0.7 (0.1) 0.1 8.0 Total construction 10.2 0.1 (0.3) 0.5 10.5 Residential real estate: Residential 1-4 family 11.4 2.0 — — 13.4 Home equity and HELOC 1.4 (0.1) (0.1) 0.2 1.4 Total residential real estate 12.8 1.9 (0.1) 0.2 14.8 Agricultural real estate 2.7 0.3 — — 3.0 Total real estate 80.5 0.8 (2.7) 0.8 79.4 Consumer: Indirect 16.7 (0.2) (2.1) 1.4 15.8 Direct and advance lines 4.6 0.7 (1.2) 0.5 4.6 Credit card 2.6 (0.4) (1.0) 0.4 1.6 Total consumer 23.9 0.1 (4.3) 2.3 22.0 Commercial: Commercial and floor plans 34.2 (5.2) (2.1) 2.1 29.0 Commercial purpose secured by 1-4 family 4.7 (0.6) (0.1) 0.4 4.4 Credit card 0.3 0.2 (0.3) 0.1 0.3 Total commercial 39.2 (5.6) (2.5) 2.6 33.7 Agricultural: Agricultural 0.7 (0.1) (0.2) — 0.4 Total agricultural 0.7 (0.1) (0.2) — 0.4 Total allowance for credit losses $ 144.3 $ (4.8) $ (9.7) $ 5.7 $ 135.5 (1) Amounts presented are exclusive of the allowance for credit losses related to unfunded commitments which are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report. Collateral-Dependent Financial Loans A collateral-dependent financial loan relies solely on the operation or sale of the collateral for repayment. In evaluating the overall risk associated with a loan, the Company considers (1) character, overall financial condition and resources, and payment record of the borrower; (2) the prospects for support from any financially responsible guarantors; and (3) the nature and degree of protection provided by the cash flow and value of any underlying collateral. The loan may become collateral-dependent when the borrower is experiencing financial difficulty and, its sources of repayment become inadequate over time. At such time, the Company develops an expectation that repayment will be provided substantially through the operation or sale of the collateral. The following tables present the amortized cost basis of collateral-dependent loans by class of loans as of the dates indicated: Collateral Type As of June 30, 2022 Business Assets Real Property Other Total Real estate $ 1.2 $ 63.6 $ — $ 64.8 Commercial 4.6 5.6 — 10.2 Agricultural — 10.5 — 10.5 Total collateral-dependent $ 5.8 $ 79.7 $ — $ 85.5 Collateral Type As of December 31, 2021 Business Assets Real Property Other Total Real estate $ 1.2 $ 7.0 $ — $ 8.2 Commercial 1.8 1.0 — 2.8 Agricultural — 0.7 — 0.7 Total collateral-dependent $ 3.0 $ 8.7 $ — $ 11.7 Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans classified in the following table as greater than 90 days past due continue to accrue interest. The following tables present the contractual aging of the Company’s recorded amortized cost basis in loans by portfolio as of the dates indicated. Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of June 30, 2022 Past Due Past Due Past Due Past Due Loans Loans (1) Loans Real estate Commercial $ 5.1 $ 2.1 $ 0.7 $ 7.9 $ 7,820.1 $ 29.7 $ 7,857.7 Construction: Land acquisition & development 0.7 0.1 — 0.8 350.8 4.1 355.7 Residential 1.0 0.4 — 1.4 443.4 — 444.8 Commercial 10.7 — — 10.7 948.3 — 959.0 Total construction loans 12.4 0.5 — 12.9 1,742.5 4.1 1,759.5 Residential 3.2 2.1 0.4 5.7 2,049.7 5.0 2,060.4 Agricultural 2.1 — 0.3 2.4 781.2 37.9 821.5 Total real estate loans 22.8 4.7 1.4 28.9 12,393.5 76.7 12,499.1 Consumer: Indirect consumer 5.3 1.4 0.2 6.9 725.2 1.8 733.9 Other consumer 0.6 0.2 — 0.8 156.3 0.2 157.3 Credit card 0.6 0.2 0.3 1.1 73.7 — 74.8 Total consumer loans 6.5 1.8 0.5 8.8 955.2 2.0 966.0 Commercial 8.4 2.1 1.0 11.5 3,010.6 13.9 3,036.0 Agricultural 10.0 0.1 — 10.1 647.5 14.4 672.0 Loans held for investment $ 47.7 $ 8.7 $ 2.9 $ 59.3 $ 17,006.8 $ 107.0 $ 17,173.1 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2021 Past Due Past Due Past Due Past Due Loans Loans (1) Loans Real estate Commercial $ 1.1 $ 1.0 $ 0.6 $ 2.7 $ 3,960.8 $ 8.0 $ 3,971.5 Construction: Land acquisition & development 0.2 — — 0.2 246.9 0.7 247.8 Residential 4.2 — — 4.2 257.8 — 262.0 Commercial — — — — 498.0 — 498.0 Total construction loans 4.4 — — 4.4 1,002.7 0.7 1,007.8 Residential 3.0 0.8 0.1 3.9 1,531.4 2.9 1,538.2 Agricultural 1.9 0.2 — 2.1 206.9 4.9 213.9 Total real estate loans 10.4 2.0 0.7 13.1 6,701.8 16.5 6,731.4 Consumer: Indirect consumer 5.1 1.4 0.4 6.9 729.0 1.7 737.6 Other consumer 0.5 0.2 0.1 0.8 128.3 0.1 129.2 Credit card 0.6 0.2 0.5 1.3 63.6 — 64.9 Total consumer loans 6.2 1.8 1.0 9.0 920.9 1.8 931.7 Commercial 4.9 0.7 1.1 6.7 1,463.8 5.0 1,475.5 Agricultural 0.7 — — 0.7 201.6 1.6 203.9 Other, including overdrafts — — — — 1.5 — 1.5 Loans held for investment $ 22.2 $ 4.5 $ 2.8 $ 29.5 $ 9,289.6 $ 24.9 $ 9,344.0 (1) As of June 30, 2022 and December 31, 2021, none of our non-accrual loans were earning interest income. Additionally, no material interest income was recognized on non-accrual loans during the three and the six months ended June 30, 2022 and 2021, respectively. There were no material reversals of accrued interest at June 30, 2022 and 2021. Troubled Debt Restructurings Modifications of performing loans are made in the ordinary course of business and are completed on a case-by-case basis through negotiation with the borrower in connection with the ongoing loan collection processes. Loan modifications are made to provide borrowers payment relief and typically include adjustments such as changes to interest rates, the implementation of interest only periods of less than twelve months, the deferment of short-term payments, and extension of amortization periods. A loan modification is considered a troubled debt restructuring if the borrower is experiencing financial difficulties and the Company, for economic or legal reasons, grants a concession to the borrower that it would not under other circumstances. Certain troubled loans are on non-accrual status at the time of debt restructuring. These restructured loans may be returned to accrual status if the borrower has exhibited sustained repayment performance in compliance with the restructuring agreement for a period of at least six months and the Company is reasonably assured of the borrower’s future performance. If the troubled debt restructuring meets these performance criteria, and the interest rate granted at the modification date is equal to or greater than the rate that the Company might grant for a new loan at the same time at comparable risk, then the loan will be reclassified to performing status and the accrual of interest will resume. Loans that return to performing status will continue to be evaluated individually for credit deterioration in the ordinary course of business. The Company renegotiated loans in troubled debt restructurings in the amount of $28.9 million as of June 30, 2022, of which $8.4 million were included in non-accrual loans and $20.5 million were on accrual status. As of June 30, 2022, the Company allocated $0.2 million of its allowance for credit losses to these loans. The Company had no material commitments to lend additional funds to borrowers whose existing loans had been renegotiated or classified as non-accrual. The Company renegotiated loans in troubled debt restructurings in the amount of $6.2 million as of December 31, 2021, of which $3.9 million were included in non-accrual loans and $2.3 million were on accrual status. As of December 31, 2021, the Company allocated $0.1 million of its allowance for credit losses to these loans. The Company had no material commitments to lend additional funds to borrowers whose existing loans had been renegotiated or classified as non-accrual. The Company had $6.4 million and $23.6 million of new troubled debt restructurings during the three and the six months ended June 30, 2022, respectively. Number of Notes Type of Concession Principal Balance at Restructure Three Months Ended June 30, 2022 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 1 $ — $ — $ — $ 0.2 $ 0.2 Residential real estate 1 — 0.1 — — 0.1 Commercial 1 — — — 0.2 0.2 Agricultural 1 — — — 5.9 5.9 Total loans restructured during period 4 $ — $ 0.1 $ — $ 6.3 $ 6.4 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories . Number of Notes Type of Concession Principal Balance at Restructure Six Months Ended June 30, 2022 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 3 $ 3.2 $ 4.2 $ — $ 0.2 $ 7.6 Residential real estate 2 — 0.6 — — 0.6 Agriculture real estate 1 — 8.9 — — 8.9 Commercial 2 — — — 0.6 0.6 Agriculture 1 — — — 5.9 5.9 Total loans restructured during period 9 $ 3.2 $ 13.7 $ — $ 6.7 $ 23.6 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories. For troubled debt restructurings that were on non-accrual status or otherwise deemed collateral-dependent before a modification, the Company may record an allowance for credit losses depending on the circumstances. In periods after modification, the Company continues to evaluate all troubled debt restructurings for possible credit deterioration and, where deterioration is observed, recognizes credit loss through the allowance. Additionally, the Company continues to work these loans through the credit cycle through charge-off, pay-off, or foreclosure. Financial effects of modifications of troubled debt restructurings may include principal loan forgiveness or other charge-offs directly related to the restructuring. The Company had no charge-offs directly related to modifying troubled debt restructurings during the three and the six months ended June 30, 2022 or 2021. The Company had no material troubled debt restructurings resulting in payment default during the previous 12 months ended June 30, 2022. The Company considers a payment default to occur on troubled debt restructurings when the loan is 90 days or more past due or the loan is placed on non-accrual status after the modification. The Company modified the terms of certain other loans with a total recorded investment of $190.8 million as of June 30, 2022, where the loan did not meet the definition of a troubled debt restructuring and the borrowers had not been experiencing financial difficulties or there were delays in a payment considered to be insignificant. The Company determines whether a borrower is experiencing financial difficulty by evaluating the probability that the borrower will be in payment default on any of its debt in the foreseeable future without the modification as required under the Company’s internal underwriting policy. Purchased Credit Deteriorated Loans (PCD) The Company analyzes all acquired loans at the time of acquisition for more-than-insignificant deterioration in credit quality since their origination date. Such loans are classified as PCD, also referred to as PCD loans. Acquired loans classified as PCD are recorded at an initial amortized cost, which is comprised of the purchase price of the loans plus the initial allowance for credit losses for the loans, and any resulting discount or premium related to factors other than credit. The Company accounts for interest income on PCD loans using the interest method, whereby any purchase discounts or premiums are accreted or amortized into interest income as an adjustment of the loan’s yield. The following table reconciles the par value, or initial amortized cost, of PCD loans acquired in the GWB acquisition as of the date of the acquisition with the purchase price (or initial fair value of the loans) as amended for measurement period adjustments as of June 30, 2022: Purchase price (initial fair value) $ 623.3 Allowance for credit losses (1) 298.2 Discount attributable to other factors (2) 57.7 Par value (unpaid principal balance) $ 979.2 (1) For acquired PCD loans, an allowance of $298.2 million was required with a corresponding increase to the amortized cost basis as of the acquisition date. For PCD loans where all or a portion of the loan balance had been previously written-off by GWB, or would be subject to write-off under the Company’s charge-off policy, a CECL allowance of $238.7 million, included as part of the grossed-up loan balance at acquisition was immediately written-off. The net impact to the allowance for PCD assets on the acquisition date was $59.5 million. (2) Non-credit discount includes the difference between the amortized cost basis and the unpaid principal balance of $39.6 million established on GWB PCD loans acquired and interest applied to principal of $18.1 million. Credit Quality Indicators As part of the on-going and continuous monitoring of the credit quality of the Company’s loan portfolio, management tracks internally assigned risk classifications of loans based on relevant information about the ability of borrowers to service their debt. The factors considered by the Company include, among other factors, the borrower’s current financial information, historical payment experience, credit documentation, public information, and current economic trends. The Company analyzes loans individually to classify the credit risk of the loans. This analysis generally includes loans with an outstanding balance greater than $1.0 million, which are generally considered non-homogeneous loans, such as commercial loans and commercial real estate loans. This analysis is performed no less than on an annual basis, depending upon the size of exposure and the contractual obligations governing the borrower’s financial reporting frequency. Homogeneous loans, including small business loans, are typically managed by payment performance. The Company internally risk rates its loans in accordance with a Uniform Classification System developed jointly by the various bank regulatory agencies. The Uniform Classification System defines three broad categories of criticized assets, which the Company uses as credit quality indicators in addition to the 6 Pass ratings in its 10-point rating scale: Special Mention — includes loans that exhibit a potential weakness in financial condition, loan structure, or documentation that warrants management’s close attention. If not promptly corrected, the potential weaknesses may result in deterioration of the repayment prospects for the loan or of the institution’s credit position at some future date. Substandard — includes loans that are inadequately protected by the current net worth and paying capacity of the borrower which have well-defined weaknesses that jeopardize the liquidation of the debt. Although the primary source of repayment for a substandard loan may not currently be sufficient, collateral or other sources of repayment are sufficient to satisfy the debt. Continuance of a substandard loan is not warranted unless positive steps are taken to improve the worthiness of the credit. Doubtful — includes loans that exhibit pronounced weaknesses based on currently existing facts, conditions, and values to a point where collection or liquidation for full repayment is highly questionable and improbable. Doubtful loans are required to be placed on non-accrual status and are assigned specific loss exposure. Loans not meeting the criteria above that are analyzed individually as part of the above-described process are considered pass-rated loans. The Company evaluates the credit quality and loan performance for the allowance for credit loan losses of the following segments based on the aforementioned risk scale for the periods indicated: June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Commercial real estate non-owner occupied: Pass $ 458.6 $ 817.2 $ 677.9 $ 536.0 $ 251.2 $ 641.7 $ 30.4 $ 3,413.0 Special mention 6.1 25.0 1.9 18.0 33.8 24.5 — 109.3 Substandard 3.2 12.8 25.0 17.7 31.6 32.0 — 122.3 Doubtful 0.3 — — 1.6 1.8 — — 3.7 Total $ 468.2 $ 855.0 $ 704.8 $ 573.3 $ 318.4 $ 698.2 $ 30.4 $ 3,648.3 Commercial real estate owner occupied: Pass $ 438.6 $ 793.8 $ 564.2 $ 307.8 $ 239.7 $ 887.2 $ 25.1 $ 3,256.4 Special mention 3.0 5.6 3.0 7.1 2.1 12.7 0.3 33.8 Substandard 10.3 2.9 3.0 5.2 4.3 26.8 0.4 52.9 Doubtful — 2.9 — — 9.4 2.0 — 14.3 Total $ 451.9 $ 805.2 $ 570.2 $ 320.1 $ 255.5 $ 928.7 $ 25.8 $ 3,357.4 Commercial multi-family: Pass $ 152.3 $ 212.8 $ 185.3 $ 54.0 $ 36.5 $ 122.7 $ 3.2 $ 766.8 Substandard — — 37.5 1.2 46.2 0.3 — 85.2 Total $ 152.3 $ 212.8 $ 222.8 $ 55.2 $ 82.7 $ 123.0 $ 3.2 $ 852.0 Land, acquisition and development: Pass $ 79.1 $ 151.9 $ 33.8 $ 26.1 $ 15.2 $ 31.7 $ 12.7 $ 350.5 Special mention — — — — 0.2 0.3 — 0.5 Substandard — 0.7 0.2 — — 0.6 — 1.5 Doubtful — 3.2 — — — — — 3.2 Total $ 79.1 $ 155.8 $ 34.0 $ 26.1 $ 15.4 $ 32.6 $ 12.7 $ 355.7 Residential construction: Pass $ 73.1 $ 138.8 $ 0.4 $ 9.7 $ 0.8 $ 6.2 $ 215.4 $ 444.4 Substandard — — — — — 0.4 — 0.4 Total $ 73.1 $ 138.8 $ 0.4 $ 9.7 $ 0.8 $ 6.6 $ 215.4 $ 444.8 Commercial construction: Pass $ 198.0 $ 432.0 $ 187.6 $ 87.2 $ 1.9 $ — $ 7.5 $ 914.2 Special mention — — 23.1 — — — — 23.1 Substandard — — — 21.7 — — — 21.7 Total $ 198.0 $ 432.0 $ 210.7 $ 108.9 $ 1.9 $ — $ 7.5 $ 959.0 Agricultural real estate: Pass $ 112.6 $ 182.2 $ 122.2 $ 70.0 $ 53.9 $ 134.1 $ 29.8 $ 704.8 Special mention 1.5 2.5 2.3 1.8 9.7 5.9 9.9 33.6 Substandard 3.3 17.6 4.0 3.2 22.0 13.7 12.6 76.4 Doubtful — 0.9 3.1 0.8 — 1.9 — 6.7 Total $ 117.4 $ 203.2 $ 131.6 $ 75.8 $ 85.6 $ 155.6 $ 52.3 $ 821.5 Commercial and floor plans: Pass $ 318.5 $ 447.6 $ 256.9 $ 151.3 $ 149.1 $ 202.6 $ 821.7 $ 2,347.7 Special mention 6.6 7.1 2.5 4.1 2.3 6.1 22.4 51.1 Substandard 13.5 1.5 3.4 2.6 3.6 8.1 11.6 44.3 Doubtful — 4.7 0.2 — — 1.6 — 6.5 Total $ 338.6 $ 460.9 $ 263.0 $ 158.0 $ 155.0 $ 218.4 $ 855.7 $ 2,449.6 June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Commercial purpose secured by 1-4 family: Pass $ 106.5 $ 147.2 $ 69.9 $ 32.7 $ 32.4 $ 47.6 $ 25.0 $ 461.3 Special mention 0.2 0.4 0.6 0.6 1.9 0.6 — 4.3 Substandard 0.4 1.3 1.2 0.3 0.6 1.3 0.1 5.2 Doubtful — 0.2 — — — — — 0.2 Total $ 107.1 $ 149.1 $ 71.7 $ 33.6 $ 34.9 $ 49.5 $ 25.1 $ 471.0 Agricultural: Pass $ 103.1 $ 91.1 $ 37.2 $ 13.4 $ 10.6 $ 1.2 $ 343.8 $ 600.4 Special mention 3.1 2.2 0.6 1.3 0.7 0.3 10.9 19.1 Substandard 22.8 6.9 5.1 0.9 1.8 0.7 4.3 42.5 Doubtful — 4.6 — — 2.5 0.9 — 8.0 Total $ 129.0 $ 104.8 $ 42.9 $ 15.6 $ 15.6 $ 3.1 $ 359.0 $ 670.0 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Commercial real estate non-owner occupied: Pass $ 507.9 $ 452.2 $ 237.9 $ 150.4 $ 76.3 $ 409.0 $ 15.3 $ 1,849.0 Special mention 0.2 3.1 2.1 — — 3.6 — 9.0 Substandard 3.9 15.3 2.3 0.7 1.0 12.4 — 35.6 Total $ 512.0 $ 470.6 $ 242.3 $ 151.1 $ 77.3 $ 425.0 $ 15.3 $ 1,893.6 Commercial real estate owner occupied: Pass $ 452.7 $ 314.9 $ 235.0 $ 151.0 $ 94.5 $ 322.5 $ 14.2 $ 1,584.8 Special mention 1.3 3.2 1.5 7.4 3.5 13.8 — 30.7 Substandard 3.8 4.3 4.7 5.4 2.7 20.3 — 41.2 Total $ 457.8 $ 322.4 $ 241.2 $ 163.8 $ 100.7 $ 356.6 $ 14.2 $ 1,656.7 Commercial multi-family: Pass $ 129.1 $ 118.6 $ 43.9 $ 15.4 $ 36.0 $ 76.7 $ 1.5 $ 421.2 Total $ 129.1 $ 118.6 $ 43.9 $ 15.4 $ 36.0 $ 76.7 $ 1.5 $ 421.2 Land, acquisition and development: Pass $ 113.0 $ 41.5 $ 34.2 $ 14.8 $ 19.8 $ 20.8 $ 1.2 $ 245.3 Special mention — 0.1 — — 0.1 0.3 — 0.5 Substandard 0.8 0.2 — 0.6 0.3 0.1 — 2.0 Total $ 113.8 $ 41.8 $ 34.2 $ 15.4 $ 20.2 $ 21.2 $ 1.2 $ 247.8 Residential construction: Pass $ 112.4 $ 7.0 $ 13.7 $ 0.9 $ — $ — $ 127.2 $ 261.2 Substandard — 0.4 — — 0.4 — — 0.8 Total $ 112.4 $ 7.4 $ 13.7 $ 0.9 $ 0.4 $ — $ 127.2 $ 262.0 Commercial construction: Pass $ 209.7 $ 141.4 $ 118.8 $ 27.6 $ — $ 0.5 $ — $ 498.0 Total $ 209.7 $ 141.4 $ 118.8 $ 27.6 $ — $ 0.5 $ — $ 498.0 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Agricultural real estate: Pass $ 58.3 $ 36.9 $ 35.1 $ 22.6 $ 11.8 $ 28.1 $ 4.9 $ 197.7 Special mention 0.1 1.3 1.2 0.1 0.1 0.9 0.9 4.6 Substandard 4.0 0.4 1.0 0.6 1.3 4.3 — 11.6 Total $ 62.4 $ 38.6 $ 37.3 $ 23.3 $ 13.2 $ 33.3 $ 5.8 $ 213.9 Commercial and floor plans: Pass $ 394.2 $ 165.7 $ 94.5 $ 73.5 $ 47.1 $ 91.3 $ 224.7 $ 1,091.0 Special mention 0.8 11.4 0.8 0.8 3.0 2.3 7.0 26.1 Substandard 1.3 2.8 1.6 2.6 0.6 4.1 2.6 15.6 Total $ 396.3 $ 179.9 $ 96.9 $ 76.9 $ 50.7 $ 97.7 $ 234.3 $ 1,132.7 Commercial purpose secured by 1-4 family: Pass $ 94.9 $ 55.0 $ 27.8 $ 23.1 $ 15.3 $ 32.2 $ 14.4 $ 262.7 Special mention — 0.2 0.2 0.5 0.1 0.6 — 1.6 Substandard 1.3 1.2 0.6 0.6 0.2 1.3 0.1 5.3 Total $ 96.2 $ 56.4 $ 28.6 $ 24.2 $ 15.6 $ 34.1 $ 14.5 $ 269.6 Agricultural: Pass $ 35.1 $ 16.2 $ 9.0 $ 5.4 $ 2.1 $ 1.6 $ 108.9 $ 178.3 Special mention 0.2 4.1 0.1 0.4 0.6 0.3 7.0 12.7 Substandard 4.9 0.7 0.6 2.5 — 0.1 2.6 11.4 Total $ 40.2 $ 21.0 $ 9.7 $ 8.3 $ 2.7 $ 2.0 $ 118.5 $ 202.4 The Company evaluates the credit quality, loan performance, and the allowance for credit losses of its residential and consumer loan portfolios based primarily on the aging status of the loan and borrower payment activity. Accordingly, loans on nonaccrual status, loans past due 90 days or more and still accruing interest, and loans modified under troubled debt restructurings are considered nonperforming for purposes of credit quality evaluation. The following tables present the recorded investment of our other loan portfolios based on the credit risk profile of loans that are performing and loans that are nonperforming as of the periods indicated: June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Residential 1-4 family: Performing $ 83.6 $ 448.6 $ 563.5 $ 106.0 $ 34.0 $ 296.2 $ 0.3 $ 1,532.2 Nonperforming — — 0.1 0.1 0.3 2.3 — 2.8 Total $ 83.6 $ 448.6 $ 563.6 $ 106.1 $ 34.3 $ 298.5 $ 0.3 $ 1,535.0 Consumer home equity and HELOC: Performing $ 9.9 $ 9.7 $ 5.8 $ 3.8 $ 6.3 $ 19.4 $ 468.0 $ 522.9 Nonperforming 0.3 0.4 — 0.1 0.2 1.4 0.1 2.5 Total $ 10.2 $ 10.1 $ 5.8 $ 3.9 $ 6.5 $ 20.8 $ 468.1 $ 525.4 Consumer indirect: Performing $ 164.9 $ 218.8 $ 162.1 $ 79.8 $ 46.2 $ 60.1 $ — $ 731.9 Nonperforming — 0.7 0.4 0.3 0.2 0.4 — 2.0 Total $ 164.9 $ 219.5 $ 162.5 $ 80.1 $ 46.4 $ 60.5 $ — $ 733.9 Consumer direct and advance line: Performing $ 31.7 $ 41.4 $ 24.7 $ 12.6 $ 9.6 $ 11.3 $ 25.9 $ 157.2 Nonperforming — — — — — 0.1 — 0.1 Total $ 31.7 $ 41.4 $ 24.7 $ 12.6 $ 9.6 $ 11.4 $ 25.9 $ 157.3 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Residential 1-4 family: Performing $ 360.9 $ 477.0 $ 74.7 $ 27.5 $ 25.7 $ 176.5 $ — $ 1,142.3 Nonperforming — 0.3 — — 0.2 0.8 — 1.3 Total $ 360.9 $ 477.3 $ 74.7 $ 27.5 $ 25.9 $ 177.3 $ — $ 1,143.6 Consumer home equity and HELOC: Performing $ 11.1 $ 7.0 $ 3.7 $ 4.8 $ 3.6 $ 12.0 $ 350.7 $ 392.9 Nonperforming 0.3 — 0.3 — 0.6 0.5 — 1.7 Total $ 11.4 $ 7.0 $ 4.0 $ 4.8 $ 4.2 $ 12.5 $ 350.7 $ 394.6 Consumer indirect: Performing $ 272.6 $ 208.6 $ 108.3 $ 64.0 $ 37.0 $ 45.0 $ — $ 735.5 Nonperforming 0.5 0.5 0.4 0.2 0.1 0.4 — 2.1 Total $ 273.1 $ 209.1 $ 108.7 $ 64.2 $ 37.1 $ 45.4 $ — $ 737.6 Consumer direct and advance line: Performing $ 42.5 $ 27.9 $ 15.0 $ 13.3 $ 5.8 $ 7.6 $ 16.9 $ 129.0 Nonperforming 0.1 — — 0.1 — — — 0.2 Total $ 42.6 $ 27.9 $ 15.0 $ 13.4 $ 5.8 $ 7.6 $ 16.9 $ 129.2 While the Company considers the performance of the loan portfolio on the allowance for credit losses, for certain credit card loan classes, the Company also evaluates credit quality based on the aging status of the loan, which was previously presented, and by payment activity of the credit card holder. The following table presents the recorded investment in credit card loans based on payment activity for the periods indicated: As of June 30, 2022 Consumer Commercial Agricultural Total Credit Card: Performing $ 74.5 $ 114.9 $ 2.0 $ 191.4 Nonperforming 0.3 0.5 — 0.8 Total credit card $ 74.8 $ 115.4 $ 2.0 $ 192.2 As of December 31, 2021 Consumer Commercial Agricultural Total Credit Card: Performing $ 64.4 $ 73.1 $ 1.5 $ 139.0 Nonperforming 0.5 0.1 — 0.6 Total credit card $ 64.9 $ 73.2 $ 1.5 $ 139.6

Other Real Estate Owned

Other Real Estate Owned	6 Months Ended
	Jun. 30, 2022
Repossessed Assets [Abstract]
Other Real Estate Owned	Other Real Estate Owned Other real estate owned is a category of real estate owned by the Company as a result of a default by the borrower. Information with respect to the Company’s other real estate owned is reflected in the following table: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 17.5 $ 2.2 $ 2.0 $ 2.5 Acquired through acquisition — — 15.8 — Additions 0.1 — 0.1 0.3 Dispositions (0.8) (0.2) (1.1) (0.8) Ending balance $ 16.8 $ 2.0 $ 16.8 $ 2.0

Derivatives and Hedging Activit

Derivatives and Hedging Activities	6 Months Ended
	Jun. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative and Hedging Activities	Derivatives and Hedging Activities The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through the management of its business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. The Company enters into derivative financial instruments, such as interest rate swap contracts to manage or hedge exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates and interest rate exposures. The Company does not enter into interest rate swap agreements for trading or speculative purposes. In the normal course of business, the Company enters into interest rate lock commitments to finance residential mortgage loans that are not designated as accounting hedges. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee, provided the loan meets underwriting guidelines, and closes within the timeframe established by the Company. Interest rate risk arises on these commitments and subsequently on closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Loan commitments related to residential mortgage loans intended to be sold are considered derivatives and are marked to market through earnings. In addition to the effects of the change in market interest rate, the fair value measurement of the derivative also contemplates the expected cash flows to be received from the counterparty from the future sale of the loan. The Company sells residential mortgage loans on either a best efforts or mandatory delivery basis. The Company mitigates the effect of the interest rate risk inherent in providing interest rate lock commitments by entering into forward loan sales contracts. The forward loan sales contracts are marked to market through earnings and are not designated as accounting hedges during the interest rate lock commitment period and through the duration of the forward loan sales contracts. Exclusive of the fair value component associated with the projected cash flows from the loan delivery to the investor, the changes in fair value related to movements in market rates of the interest rate lock commitments and the forward loan sales contracts generally move in opposite directions, and the net impact of changes in these valuations on net income during the loan commitment period is generally inconsequential. When the loan is funded to the borrower, the interest rate lock commitment derivative expires, and the Company records a loan held for sale. The forward loan sales contract acts as a hedge against the variability in cash to be received from the loan sale. The changes in measurement of the estimated fair values of the interest rate lock commitments and forward loan sales contracts are included in mortgage banking revenues in the accompanying consolidated statements of income. The Company also enters into certain interest rate swap contracts that are not designated as hedging instruments. These derivative contracts relate to transactions in which the Company enters into an interest rate swap with a client while at the same time entering into an offsetting interest rate swap with a third-party financial institution. Because the Company acts as an intermediary for the client, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact the Company’s results of operations. Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. During 2021 and the first quarter of 2022, such derivatives were used to hedge the variable cash flows associated with the existing variable-rate borrowings (trust preferred securities). For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in accumulated other comprehensive (loss) income and subsequently reclassified into interest expense in the same period(s) during which the hedged transaction affects earnings. Amounts reported in accumulated other comprehensive (loss) income related to derivatives will be reclassified as interest expense when interest payments are made on the Company’s variable-rate liabilities. During the next twelve months, the Company estimates that no material amounts will be reclassified as an increase to interest expense. Fair Value Hedges of Interest Rate Risk The Company is exposed to changes in the fair value of fixed-rate assets due to changes in benchmark interest rates. The Company uses interest rate swaps to manage its exposure to changes in fair value on these instruments attributable to changes in the designated benchmark interest rate. Interest rate swaps designated as fair value hedges involve the payment of fixed-rate amounts to a counterparty in exchange for the Company receiving variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. During 2021, the Company entered into two forward starting, fixed interest rate fair value hedges associated with U.S. Treasury securities. During the second quarter of 2022, the Company terminated the $500.0 million, two-year forward starting, three-year pay-fixed interest rate swap, resulting in a $23.3 million gain that will be accreted into income through May 2026. For derivatives designated and that qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in interest income. The following amounts were recorded on the balance sheet related to cumulative basis adjustment for fair value hedges for the periods indicated: June 30, 2022 December 31, 2021 Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Available-for-sale securities $ 189.5 $ (10.5) $ 695.6 $ (4.4) Non-designated Hedge Derivatives Derivatives not designated as hedges are not speculative and result from a service the Company provides to certain customers. The Company executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are simultaneously hedged by offsetting derivatives that the Company executes with a third party, such that the Company minimizes its net risk exposure resulting from such transactions. As the interest rate derivatives associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized directly in earnings. Risk Participation Agreements The Company acquired from GWB risk participation agreements under which it assumes credit risk associated with a borrower’s performance related to derivative contracts. The Company only enters into these credit risk participation agreements in instances in which the Company is also a party to the related loan participation agreements for such borrowers. The Company manages its credit risk under risk participation agreements by monitoring the creditworthiness of the borrower, based on its normal credit review process. The following table summarizes the fair values of our derivative instruments on a gross and net basis for the periods indicated. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements, but after the variation margin payments with central clearing organizations have been applied as settlement, as applicable. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. June 30, 2022 December 31, 2021 Notional Amount Balance Sheet Location Estimated Notional Amount Balance Sheet Location Estimated Derivatives designated as hedges: Interest rate swap contracts $ 200.0 $ 10.3 $ 700.0 $ 4.1 Derivatives not designated as hedges: Interest rate swap contracts 1,758.7 14.3 913.9 22.2 Interest rate lock commitments 28.6 0.2 77.3 1.8 Forward loan sales contracts 34.6 — — — Derivative assets in the balance sheet $ 2,021.9 Other Assets $ 24.8 $ 1,691.2 Other Assets $ 28.1 Derivatives designated as hedges: Interest rate swap contracts $ — $ — $ 87.6 $ 0.1 Derivatives not designated as hedges: Interest rate swap contracts 1,758.7 99.2 913.9 18.1 Risk participation agreements 108.5 0.2 — — Forward loan sales contracts — — 102.4 — Derivative liabilities in the balance sheet $ 1,867.2 Accrued Expenses $ 99.4 $ 1,103.9 Accrued Expenses $ 18.2 There were no material effects of derivative instruments in fair value or cash flow hedge accounting on accumulated other comprehensive (loss) income during the three and the six months ended June 30, 2022 or 2021. There were no material effects from the Company’s fair value or cash flow hedged derivative financial instruments on the income statement during the three and the six months ended June 30, 2022 or 2021. The table below presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the income statement for the periods indicated: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative Interest rate lock commitments Mortgage banking revenues $ 1.0 $ 0.2 Mortgage banking revenues $ 1.5 $ 0.5 The Company recorded fee revenues of $1.1 million and $0.1 million for the three months ended June 30, 2022 and June 30, 2021, respectively, and $3.1 million and $1.2 million for the six months ended June 30, 2022 and June 30, 2021, respectively. The Company includes swap fee revenues in other service charges, commissions, and fees. The tables below present the gross presentation, the effects of offsetting, and a net presentation of the Company’s derivatives as of the periods indicated: June 30, 2022 Gross Assets Recognized Gross Assets Offset in the Balance Sheet Net Assets in the Balance Sheet Financial Instruments Cash Collateral Received Net Amount Interest rate swap contracts $ 24.6 $ — $ 24.6 $ — $ 23.7 $ 0.9 Mortgage related derivatives 0.2 — 0.2 — — 0.2 Total derivatives 24.8 — 24.8 — 23.7 1.1 Total assets $ 24.8 $ — $ 24.8 $ — $ 23.7 $ 1.1 Gross Liabilities Recognized Gross Liabilities Offset in the Balance Sheet Net Liabilities in the Balance Sheet Financial Instruments Cash Collateral Posted Net Amount Interest rate swap contracts $ 99.2 $ — $ 99.2 $ — $ — $ 99.2 Risk participation agreements 0.2 — 0.2 — — 0.2 Total derivatives 99.4 — 99.4 — — 99.4 Repurchase agreements 1,234.7 — 1,234.7 — 1,234.7 — Total liabilities $ 1,334.1 $ — $ 1,334.1 $ — $ 1,234.7 $ 99.4 December 31, 2021 Gross Assets Recognized Gross Assets Offset in the Balance Sheet Net Assets in the Balance Sheet Financial Instruments Cash Collateral Received Net Amount Interest rate swap contracts $ 26.3 $ — $ 26.3 $ — $ 8.0 $ 18.3 Mortgage related derivatives 1.8 — 1.8 — — 1.8 Total derivatives 28.1 — 28.1 — 8.0 20.1 Total assets $ 28.1 $ — $ 28.1 $ — $ 8.0 $ 20.1 Gross Liabilities Recognized Gross Liabilities Offset in the Balance Sheet Net Liabilities in the Balance Sheet Financial Instruments Cash Collateral Posted Net Amount Interest rate swap contracts $ 18.2 $ — $ 18.2 $ — $ — $ 18.2 Total derivatives 18.2 — 18.2 — — 18.2 Repurchase agreements 1,051.1 — 1,051.1 — 1,051.1 — Total liabilities $ 1,069.3 $ — $ 1,069.3 $ — $ 1,051.1 $ 18.2 Credit-risk-related Contingent Feature The Company has agreements with each of its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well / adequately capitalized institution, then in certain instances the Company could be required to post additional capital and in certain instances the counterparty would have the right to terminate the derivative positions and the Company would be required to settle its obligations under the agreements. As of June 30, 2022, the Company had no derivatives in a net liability position.

Capital Stock

Capital Stock	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Capital Stock	Capital Stock On February 1, 2022, the Company issued 46,879,601 shares of its Class A common stock with an aggregate value of approximately $1.7 billion as consideration for the acquisition of Great Western. During the six months ended June 30, 2022 and 2021, the Company also issued 33,769 shares and 19,081 shares, respectively, of its Class A common stock to directors for their annual service on the Company's board of directors. The aggregate value of the shares issued to directors is included in employee benefits in the consolidated statement of income and in stock-based compensation expense in the consolidated statements of changes in stockholders' equity. On March 25, 2022, all outstanding shares of the Company’s Class B common stock automatically converted into shares of the Company’s Class A common stock on a one-for-one basis, pursuant to the terms of the Company’s Third Amended and Restated Articles of Incorporation, as amended (the “Charter”). No additional shares of Class B common stock are permitted to be issued. The conversion occurred automatically pursuant to the Company’s Charter because the number of the Company’s outstanding shares of Class B common stock represented on March 25, 2022, the record date for determining the shareholders of the Company entitled to notice of, and to vote at, the Company’s 2022 Annual Meeting of Shareholders, was less than twenty percent (20%) of the aggregate number of all of the outstanding shares of Class A common stock and Class B common stock of the Company. The former holders of Class B common stock now hold Class A common stock with the same voting powers, preferences, rights and qualifications, limitations and restrictions as the other holders of Class A common stock. All shares of the Company’s outstanding capital stock are now composed solely of shares of Class A common stock and are entitled to one vote per share. The Company’s Class A common stock will continue to trade on the NASDAQ Stock Market under the ticker symbol “FIBK”. On May 25, 2022, the Company’s board of directors adopted a new stock repurchase program to replace the program that had been in place since 2019 and had 1,889,158 shares of Class A common stock remaining to be purchased thereunder. Under the new stock repurchase program, the Company may repurchase up to 5.0 million of its outstanding shares of Class A common stock. There were 1,720,700 shares repurchased and retired under the new program during the three months ended June 30, 2022 of our Class A common stock at a total cost of $64.3 million, including costs and commissions, at an average cost of $37.38 per share. The shares of common stock repurchased during the period represented 34.4% of the total 5.0 million shares authorized to be repurchased. As of June 30, 2022, there were 3.3 million shares remaining authorized under the repurchase program. All other stock repurchases during the six months ended June 30, 2022 and 2021, were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company’s equity compensation plans.

Earnings per Common Share

Earnings per Common Share	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common ShareBasic earnings per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period presented, excluding unvested restricted stock. Diluted earnings per share is calculated by dividing net income by the weighted average number of common shares determined for the basic earnings per share computation plus the dilutive effects of stock-based compensation using the treasury stock method. The following table sets forth the computation of basic and diluted earnings per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Net income $ 64.1 $ 42.5 $ 30.7 $ 93.9 Weighted average common shares outstanding for basic earnings per share computation 109,106,891 61,657,593 101,025,926 61,624,917 Dilutive effects of stock-based compensation 24,827 70,228 50,405 98,225 Weighted average common shares outstanding for diluted earnings per common share computation 109,131,718 61,727,821 101,076,331 61,723,142 Basic earnings per common share $ 0.59 $ 0.69 $ 0.30 $ 1.52 Diluted earnings per common share $ 0.59 $ 0.69 $ 0.30 $ 1.52 Anti-dilutive unvested time restricted stock 218,033 84,165 61,058 90,538

Regulatory Capital

Regulatory Capital	6 Months Ended
	Jun. 30, 2022
Banking and Thrift, Other Disclosures [Abstract]
Regulatory Capital	Regulatory Capital As of June 30, 2022 and December 31, 2021, the Company exceeded all capital adequacy requirements to which it is subject. Actual capital amounts and ratios for the Company and its subsidiary Bank, as of June 30, 2022 and December 31, 2021 are presented in the following tables: Actual Minimum Required for Capital Adequacy Purposes For Capital Adequacy Purposes Plus Capital Conservation Buffer Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements(1) June 30, 2022 Amount Ratio Amount Ratio Amount Ratio Amount Ratio Total risk-based capital: Consolidated $ 2,908.7 13.60 % $ 1,710.7 8.00 % $ 2,245.2 10.50 % $ 2,138.3 10.00 % FIB 2,743.7 12.87 1,705.5 8.00 2,238.5 10.50 2,131.9 10.00 Tier 1 risk-based capital: Consolidated 2,451.4 11.46 1,283.0 6.00 1,817.6 8.50 1,710.7 8.00 FIB 2,544.0 11.93 1,279.1 6.00 1,812.1 8.50 1,705.5 8.00 Common equity tier 1 risk-based capital: Consolidated 2,451.4 11.46 962.2 4.50 1,496.8 7.00 1,389.9 6.50 FIB 2,544.0 11.93 959.3 4.50 1,492.3 7.00 1,385.7 6.50 Leverage capital ratio: Consolidated 2,451.4 7.72 1,269.5 4.00 1,269.5 4.00 1,586.8 5.00 FIB 2,544.0 8.03 1,267.0 4.00 1,267.0 4.00 1,583.7 5.00 Actual Minimum Required for Capital Adequacy Purposes For Capital Adequacy Purposes Plus Capital Conservation Buffer Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements(1) December 31, 2021 Amount Ratio Amount Ratio Amount Ratio Amount Ratio Total risk-based capital: Consolidated $ 1,659.3 14.11 % $ 940.9 8.00 % $ 1,235.0 10.50 % $ 1,176.2 10.00 % FIB 1,472.5 12.56 938.0 8.00 1,231.1 10.50 1,172.5 10.00 Tier 1 risk-based capital: Consolidated 1,469.0 12.49 705.7 6.00 999.7 8.50 940.9 8.00 FIB 1,382.2 11.79 703.5 6.00 996.6 8.50 938.0 8.00 Common equity tier 1 risk-based capital: Consolidated 1,384.8 11.77 529.3 4.50 823.3 7.00 764.5 6.50 FIB 1,382.2 11.79 527.6 4.50 820.8 7.00 762.1 6.50 Leverage capital ratio: Consolidated 1,469.0 7.68 765.5 4.00 765.5 4.00 956.9 5.00 FIB 1,382.2 7.24 764.1 4.00 764.1 4.00 955.1 5.00 (1) The ratios to meet the requirements to be deemed “well-capitalized” are only applicable to FIB. However, the Company manages its capital position as if the requirements apply to the consolidated company and has presented the ratios as if they also applied on a consolidated basis. In connection with the adoption of the Current Expected Credit Loss

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the normal course of business, the Company is involved in various claims and litigation. The Company establishes accruals for legal matters when potential losses associated with the actions become probable and the amount of loss can be reasonably estimated. There is no assurance that the ultimate resolution of these matters will not significantly exceed the amounts that the Company has accrued. Accruals for legal matters are based on management’s best judgment after consultation with counsel and others. In the opinion of management, following consultation with legal counsel, the ultimate liability or disposition of all such claims and litigation is not expected to have a material adverse effect on the consolidated financial condition, results of operations, or liquidity of the Company. As of June 30, 2022, the Company had commitments under construction contracts of $3.4 million.

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	6 Months Ended
	Jun. 30, 2022
Financial Instruments with Off-Balance Sheet Risk [Abstract]
Financial Instruments with Off-Balance Sheet Risk	Financial Instruments with Off-Balance Sheet Risk In the normal course of business, the Company is a party to financial instruments with off-balance sheet risk to meet the financing needs of its clients. These financial instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of amounts recorded in the consolidated balance sheets. Commitments to extend credit are agreements to lend to a client so long as there is no violation of any condition established in the commitment contract. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a client to a third party. The credit risk involved in issuing letters of credit is essentially the same as the credit risk involved in extending loan facilities to clients. The Company’s policy for obtaining collateral, and determining the nature of such collateral, is essentially the same as in the Company’s policies for making commitments to extend credit. The estimated fair value of the obligation undertaken by the Company in issuing standby letters of credit is included in accounts payable and accrued expenses in the Company’s consolidated balance sheets. The following table presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 6.2 $ 3.4 $ 3.8 $ 3.7 Provision for (reversal of) credit loss expense — — 2.4 (0.3) Ending balance of allowance for off-balance sheet credit losses $ 6.2 $ 3.4 $ 6.2 $ 3.4 June 30, 2022 December 31, 2021 Unused credit card lines $ 811.9 $ 681.6 Commitments to extend credit 4,840.8 2,539.8 Standby letter of credit 91.6 57.5

Other Comprehensive Income_Loss

Other Comprehensive Income/Loss	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Other Comprehensive Income/Loss	Other Comprehensive Loss The gross amounts of each component of other comprehensive loss and the related tax effects are as follows: Pre-tax Tax Expense (Benefit) Net of Tax Three Months Ended June 30, 2022 2021 2022 2021 2022 2021 Investment securities available-for sale: Change in net unrealized loss during period $ (161.6) $ (0.8) $ (45.2) $ (0.2) $ (116.4) $ (0.6) Reclassification adjustment for net loss included in net income 0.1 0.1 — — 0.1 0.1 Net change in unamortized (losses) gains on available-for-sale securities transferred into held-to-maturity (0.9) 24.8 (0.2) 6.3 (0.7) 18.5 Change in net unrealized loss (gain) on derivatives (15.0) (0.8) (4.2) (0.2) (10.8) (0.6) Total other comprehensive (loss) income $ (177.4) $ 23.3 $ (49.6) $ 5.9 $ (127.8) $ 17.4 Pre-tax Tax Expense (Benefit) Net of Tax Six Months Ended June 30, 2022 2021 2022 2021 2022 2021 Investment securities available-for sale: Change in net unrealized loss during period $ (414.2) $ (67.6) $ (107.9) $ (17.2) $ (306.3) $ (50.4) Reclassification adjustment for net loss included in net income 0.2 0.1 — — 0.2 0.1 Reclassification adjustment for securities transferred from held-to-maturity to available-for-sale 0.2 — 0.1 — 0.1 — Net change in unamortized (losses) gains on available-for-sale securities transferred into held-to-maturity (23.9) 24.8 (5.9) 6.3 (18.0) 18.5 Change in net unrealized loss (gain) on derivatives 6.3 (0.9) 1.1 (0.2) 5.2 (0.7) Total other comprehensive loss $ (431.4) $ (43.6) $ (112.6) $ (11.1) $ (318.8) $ (32.5) The components of accumulated other comprehensive loss, net of related tax effects, are as follows: June 30, 2022 December 31, 2021 Net unrealized loss on investment securities available-for-sale $ (333.6) $ (29.0) Net unrealized (loss) gain on investment securities transferred to held-to-maturity (3.9) 15.0 Net unrealized gain on derivatives 7.7 3.0 Net accumulated other comprehensive loss $ (329.8) $ (11.0)

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs to measure fair value are as follows: • Level 1 - Quoted prices in active markets for identical assets or liabilities • Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities • Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of assets or liabilities The methodologies used by the Company in determining the fair values of each class of financial instruments are based primarily on independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date, and therefore, are classified within Level 2 of the valuation hierarchy. There have been no significant changes in the valuation techniques during the three and the six months ended June 30, 2022 and 2021. The Company’s policy is to recognize transfers between levels as of the end of the reporting period. Transfers in and out of Level 1, Level 2, and Level 3 are recognized on the actual transfer date. There were no transfers between fair value hierarchy levels during the three and the six months ended June 30, 2022 and 2021. Further details on the methods used to estimate the fair value of each class of financial instruments above are discussed below: Investment Debt Securities Available-for-Sale . The Company obtains fair value measurements for investment securities from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information, and the investment’s terms and conditions, among other things. Vendors chosen by the Company are widely recognized vendors whose evaluations support the pricing functions of financial institutions, investment and mutual funds, and portfolio managers. If needed, a broker may be utilized to determine the reported fair value of investment securities. Loans Held for Sale. Fair value measurements for residential mortgage loans held for sale are obtained from an independent pricing service. The fair value measurements consider observable data that may include binding contracts or quotes or bids from third party investors as well as loan level pricing adjustments. Commercial and agricultural loans held for sale are derived from quotes or bids from third party investors. Interest Rate Swap Contracts. Fair values for derivative interest rate swap contracts are based upon the estimated amounts to settle the contracts considering current interest rates and are calculated using discounted cash flows that are observable or that can be corroborated by observable market data. The inputs used to determine fair value include the three-month LIBOR forward curve to estimate variable rate cash inflows and the Secured Overnight Financing Rate to estimate the discount rate. The estimated variable rate cash inflows are compared to the fixed rate outflows and such difference is discounted to a present value to estimate the fair value of the interest rate swaps. The change in the value of derivative assets attributable to basis risk, or the risk that offsetting investments in a hedging strategy will not experience price changes in entirely opposite directions, was not significant in the reported periods. The Company also obtains and compares the reasonableness of the pricing from an independent third party. For purposes of potential valuation adjustments to our derivative positions, we evaluate both our credit risk and the credit risk of our counterparties as well as ours. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods. Interest Rate Lock Commitments. Fair value measurements for interest rate lock commitments are obtained from an independent pricing service. The fair value measurements consider observable data that may include prices available from secondary market investors taking into consideration various characteristics of the loan, including the loan amount, interest rate, value of the servicing, and loan to value ratio, among other things. Observable data is then adjusted to reflect changes in interest rates, the Company’s estimated pull-through rate, and estimated direct costs necessary to complete the commitment into a closed loan net of origination, and processing fees collected from the borrower. Forward Loan Sales Contracts. The fair value measurements for forward loan sales contracts are obtained from an independent pricing service. The fair value measurements consider observable data that includes sales of similar loans. Deferred Compensation Plan Assets and Liabilities. The fair values of deferred compensation plan assets and liabilities are based primarily on the use of independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date. These investments are in the same funds and purchased in the same amounts as the participants’ selected investments, which represent the underlying liabilities to plan participants. Deferred compensation plan liabilities are recorded at amounts due to participants, based on the fair value of participants’ selected investments. Financial assets and financial liabilities measured at fair value on a recurring basis are as follows: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Balance Quoted Prices in Significant Other Significant Investment debt securities available-for-sale: U.S. Treasury notes $ 809.8 $ 809.8 $ — $ — State, county, and municipal securities 282.2 — 282.2 — Obligations of U.S. government agencies 225.9 — 225.9 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 4,815.4 — 4,815.4 — Private mortgage-backed securities 253.0 — 253.0 — Collateralized loan obligations 1,094.0 — 1,094.0 — Corporate securities 260.8 — 260.8 — Loans held for sale 127.4 — 127.4 — Derivative assets: Interest rate swap contracts 24.6 — 24.6 — Interest rate lock commitments 0.2 — 0.2 — Derivative liabilities: Interest rate swap contracts 99.2 — 99.2 — Risk participation agreements 0.2 — 0.2 — Deferred compensation plan assets 19.3 — 19.3 — Deferred compensation plan liabilities 19.3 — 19.3 — Fair Value Measurements at Reporting Date Using As of December 31, 2021 Balance Quoted Prices in Significant Other Significant Investment debt securities available-for-sale: U.S. Treasury notes $ 684.7 $ 684.7 $ — $ — State, county and municipal securities 427.5 — 427.5 — Obligations of U.S. government agencies 346.9 — 346.9 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 2,018.1 — 2,018.1 — Private mortgage-backed securities 173.4 — 173.4 — Collateralized loan obligations 899.4 — 899.4 — Corporate securities 270.5 — 270.5 — Loans held for sale 30.1 — 30.1 — Derivative assets: Interest rate swap contracts 26.3 — 26.3 — Interest rate lock commitments 1.8 — 1.8 — Derivative liabilities Interest rate swap contracts 18.2 — 18.2 — Deferred compensation plan assets 21.4 — 21.4 — Deferred compensation plan liabilities 21.4 — 21.4 — Additionally, from time to time, certain assets are measured at fair value on a non-recurring basis. Adjustments to fair value generally result from the application of lower-of-cost-or-market accounting or write-downs of individual assets due to credit deterioration. The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Significant Collateral dependent loans $ 85.5 $ — $ — $ 85.5 Other real estate owned 16.8 — — 16.8 Long-lived assets to be disposed of by sale 7.1 — — 7.1 Fair Value Measurements at Reporting Date Using As of December 31, 2021 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Significant Collateral dependent loans $ 11.7 $ — $ — $ 11.7 Other real estate owned 2.0 — — 2.0 Long-lived assets to be disposed of by sale 1.3 — — 1.3 Collateral-dependent Loans. Collateral-dependent loans are reported at the fair value of the underlying collateral if repayment is expected solely from collateral. The collateral-dependent loans are reported at fair value through specific valuation allowance allocations. In addition, when it is determined that the fair value of a collateral-dependent loan is less than the recorded investment in the loan, the carrying value of the loan is adjusted to fair value through a charge to the allowance for credit losses. Collateral values are estimated using independent appraisals and management estimates of current market conditions. As of June 30, 2022 and December 31, 2021, the Company had collateral-dependent loans with a carrying and fair value of $85.5 million and $11.7 million, respectively. OREO. The fair values of OREO are estimated using independent appraisals and management estimates of current market conditions. Upon initial recognition, write-downs based on the foreclosed asset’s fair value at foreclosure are reported through charges to the allowance for credit losses. Periodically, the fair value of foreclosed assets is remeasured with any subsequent write-downs charged to OREO expense in the period in which they are identified. The Company had no material write downs on OREO properties during the six months ended June 30, 2022 and 2021, respectively. Long-lived Assets to be Disposed of by Sale. Long-lived assets to be disposed of by sale are carried at the lower of carrying value or fair value less estimated costs to sell. The fair values of long-lived assets to be disposed of by sale are based upon observable market data and management estimates of current market conditions. As of June 30, 2022, the Company had long-lived assets to be disposed of by sale with carrying and fair values aggregating $7.1 million, with no write-downs charged to other expense. As of December 31, 2021, the Company had long-lived assets to be disposed of by sale with carrying and fair values aggregating $1.3 million, with no write-downs charged to other expense. The following table presents additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair values: Fair Value As of June 30, 2022 December 31, 2021 Valuation Unobservable Range Collateral dependent loans $ 85.5 $ 11.7 Appraisal Appraisal adjustment 1% - 18% (7%) Other real estate owned 16.8 2.0 Appraisal Appraisal adjustment 0% - 0% 0% Long-lived assets to be disposed of by sale 7.1 1.3 Appraisal Appraisal adjustment 0% - 0% 0% The Company is required to disclose the fair value of financial instruments for which it is practical to estimate fair value. The methodologies for estimating the fair value of financial instruments that are measured at fair value on a recurring or non-recurring basis are discussed above. The methodologies for estimating the fair value of other financial instruments are discussed below. For financial instruments bearing a variable interest rate where no credit risk exists, it is presumed that recorded book values are reasonable estimates of fair value. Financial Assets. Carrying values of cash, cash equivalents, and accrued interest receivable approximate fair values due to the liquid and/or short-term nature of these instruments. Fair values for investment securities held-to-maturity are obtained from an independent pricing service, which considers observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information, and the investment’s terms and conditions, among other things. Fair values of fixed rate loans and variable rate loans that reprice on an infrequent basis are estimated by discounting future cash flows using current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality using an exit price notion. Carrying values of variable rate loans that reprice frequently, and with no change in credit risk, approximate the fair values of these instruments. Financial Liabilities. The fair values of demand deposits, savings accounts, securities sold under repurchase agreements, and accrued interest payable are the amounts that are payable on demand at the reporting date. The fair values of fixed-maturity certificates of deposit are estimated using external market rates that are currently offered for deposits that have similar remaining maturities. The fair values of derivative liabilities are obtained from an independent pricing service, which considers observable data that may include the three-month LIBOR forward curve, the federal funds effective swap rate and cash flows, among other things. The carrying values of the interest-bearing demand notes to the United States Treasury are deemed an approximation of fair values due to the frequent repayment and repricing at market rates. The fixed and floating rate subordinated debentures, floating rate subordinated term loan, notes payable to the FHLB, fixed rate subordinated term debt, and capital lease obligation are estimated by discounting future cash flows using current rates for advances that have similar characteristics. Commitments to Extend Credit and Standby Letters of Credit. The fair value of commitments to extend credit and standby letters of credit, based on fees currently charged to enter into similar agreements, is not significant. The estimated fair values of financial instruments that are reported in the Company’s consolidated balance sheets, and are segregated by the level of the valuation inputs within the fair value hierarchy that are utilized to measure fair value, are as follows: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Carrying Amount Estimated Quoted Prices in Active Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 1,059.3 $ 1,059.3 $ 1,059.3 $ — $ — Securities purchased under agreement to resell 202.2 202.2 — 202.2 — Investment debt securities available-for-sale 7,741.1 7,741.1 809.8 6,931.3 — Investment debt securities held-to-maturity 3,130.0 2,860.5 293.1 2,567.4 — Accrued interest receivable 90.6 90.6 — 90.6 — Mortgage servicing rights, net 32.1 37.0 — 37.0 — Loans held for sale 127.4 127.4 — 127.4 — Net loans held for investment 16,942.1 16,874.0 — 16,788.5 85.5 Derivative assets 24.8 24.8 — 24.8 — Deferred compensation plan assets 19.3 19.3 — 19.3 — Total financial assets $ 29,368.9 $ 29,036.2 $ 2,162.2 $ 26,788.5 $ 85.5 Financial liabilities: Total deposits, excluding time deposits $ 25,368.1 $ 25,368.1 $ 25,368.1 $ — $ — Time deposits 1,495.7 1,467.2 — 1,467.2 — Securities sold under repurchase agreements 1,234.7 1,234.7 — 1,234.7 — Accrued interest payable 4.3 4.3 — 4.3 — Long-term debt 120.4 119.3 — 119.3 — Subordinated debentures held by subsidiary trusts 163.1 157.5 — 157.5 — Derivative liabilities 99.4 99.4 — 99.4 — Deferred compensation plan liabilities 19.3 19.3 — 19.3 — Total financial liabilities $ 28,505.0 $ 28,469.8 $ 25,368.1 $ 3,101.7 $ — Fair Value Measurements at Reporting Date Using As of December 31, 2021 Carrying Amount Estimated Quoted Prices in Active Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 2,344.8 $ 2,344.8 $ 2,344.8 $ — $ — Investment debt securities available-for-sale 4,820.5 4,820.5 684.7 4,135.8 — Investment debt securities held-to-maturity 1,687.6 1,667.5 — 1,667.5 — Accrued interest receivable 47.4 47.4 — 47.4 — Mortgage servicing rights, net 28.2 28.2 — 28.2 — Loans held for sale 30.1 30.1 — 30.1 — Net loans held for investment 9,209.4 9,254.3 — 9,242.6 11.7 Derivative assets 28.1 28.1 — 28.1 — Deferred compensation plan assets 21.4 21.4 — 21.4 — Total financial assets $ 18,217.5 $ 18,242.3 $ 3,029.5 $ 15,201.1 $ 11.7 Financial liabilities: Total deposits, excluding time deposits $ 15,303.1 $ 15,303.1 $ 15,303.1 $ — $ — Time deposits 966.5 963.1 — 963.1 — Securities sold under repurchase agreements 1,051.1 1,051.1 — 1,051.1 — Accrued interest payable 3.7 3.7 — 3.7 — Long-term debt 112.4 120.7 — 120.7 — Subordinated debentures held by subsidiary trusts 87.0 85.5 — 85.5 — Derivative liabilities 18.2 18.2 — 18.2 — Deferred compensation plan liabilities 21.4 21.4 — 21.4 — Total financial liabilities $ 17,563.4 $ 17,566.8 $ 15,303.1 $ 2,263.7 $ —

Recent Authoritative Accounting

Recent Authoritative Accounting Guidance	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Recent Authoritative Accounting Guidance	Recent Authoritative Accounting Guidance ASU 2020-04, “Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Accounting.” In March 2020, the FASB issued ASU 2020-04, which provides temporary exceptions that are optional for applying GAAP to loan and lease agreements, derivative contracts, and other transactions affected by the anticipated transition away from LIBOR toward new interest rate benchmarks. For transactions that are modified because of reference rate reform and that meet certain scope guidance (i) modifications of loan agreements should be accounted for by prospectively adjusting the effective interest rate, with such modification considered to be "minor" so that any existing unamortized origination fees/costs will carry forward and continue to be amortized and (ii) modifications of lease agreements should be accounted for as a continuation of the existing agreement with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required for modifications will not be accounted for as separate contracts. ASU 2020-04 is effective March 12, 2020 through December 31, 2022. An entity may elect to apply ASU 2020-04 for contract modifications as of January 1, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic within the Codification, the amendments in this ASU must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company adopted certain elections related to cash flow hedges which did not have a significant impact on the Company’s financial position or results of operations. The Company is currently evaluating the impact of the adoption of other expedients in the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-01, “ Reference Rate Reform (Topic 848) ” In January 2021, the FASB issued ASU 2021-01, Reference Rate Reform Topic 848 , that clarifies certain exceptions that are optional in Topic 848 for contract modifications and hedge accounting and apply those exceptions to derivatives that are affected by the discounting transition. An entity may elect to apply the amendments in this ASU on a full retrospective basis as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or on a prospective basis to new modifications from any date within an interim period that includes or is subsequent to the date of the issuance of a final ASU. If an entity elects to apply any of the amendments in this ASU for an eligible hedging relationship, any adjustments as a result of those elections must be reflected as of the date the entity applies the election. The amendments in this ASU do not apply to contract modifications made, new hedging relationships entered into, or existing hedging relationships evaluated for effectiveness in periods after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that apply certain exceptions that are optional in which the accounting effects of the hedging activity are recorded through the end of the hedging relationship (including periods after December 31, 2022). The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-08, “ Business Combinations (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers ” In October 2021, the FASB issued ASU 2021-08, Business Combinations Topic 805, Accounting for Contract Assets and Contract Liabilities from Contracts with Customers , to address diversity in practice and inconsistency related to the accounting for revenue contracts with customers acquired in a business combination. The amendments require that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606 as if it had originated the contracts. The amendments also provide certain practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from revenue contracts in a business combination and applies to contract assets and contract liabilities from other contracts to which the provisions of Topic 606 apply. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption is permitted, including in any interim period, for public business entities for periods for which financial statements have not yet been issued, and for all other entities for periods for which financial statements have not yet been made available for issuance. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-01, “ Derivatives and Hedging (Topic 815), Fair Value Hedging—Portfolio Layer Method ” In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging Topic 815, Fair Value Hedging—Portfolio Layer Method that clarifies the accounting for and promotes consistency in the reporting of hedge basis adjustments applicable to both a single hedged layer and multiple hedged layers. The amendments allow nonprepayable financial assets also to be included in a closed portfolio hedged using the portfolio layer method. That expanded scope permits an entity to apply the same portfolio hedging method to both prepayable and nonprepayable financial assets, thereby allowing consistent accounting for similar hedges. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption in an interim period is permitted for public business entities, with the effect of adopting the amendments related to basis adjustments reflected as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-02, “ Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings and Vintage Disclosures ” In March 2022, the FASB issued ASU 2022-02, Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings (TDRs) and Vintage Disclosures that eliminate the accounting guidance for TDRs by creditors in Subtopic 310-40, Receivables—Troubled Debt Restructurings by Creditors, while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Rather than applying the recognition and measurement guidance for TDRs, an entity must apply the loan refinancing and restructuring guidance to determine whether a modification results in a new loan or a continuation of an existing loan. The amendment also requires an entity disclose current-period gross writeoffs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Entities should apply the amendments prospectively except for the transition method related to the recognition and measurement of TDRs, an entity has the option to apply a modified retrospective transition method, resulting in a cumulative-effect adjustment to retained earnings in the period of adoption. Early adoption of the amendments are permitted, including adoption in an interim period. If an entity elects to early adopt the amendments in an interim period, the guidance should be applied as of the beginning of the fiscal year that includes the interim period. An entity may elect to early adopt the amendments about TDRs and related disclosure enhancements separately from the amendments related to vintage disclosures. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Subsequent events have been evaluated for potential recognition and disclosure through the date the Company’s financial statements were filed with the SEC. On July 25, 2022, the Company declared a quarterly dividend to common shareholders of $0.41 per share, to be paid on August 19, 2022 to shareholders of record as of August 9, 2022. No other undisclosed events requiring recognition or disclosure were identified.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Fair Value Measurements	Fair value is defined as the price that would be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs to measure fair value are as follows: • Level 1 - Quoted prices in active markets for identical assets or liabilities • Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities • Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of assets or liabilities The methodologies used by the Company in determining the fair values of each class of financial instruments are based primarily on independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date, and therefore, are classified within Level 2 of the valuation hierarchy. There have been no significant changes in the valuation techniques during the three and the six months ended June 30, 2022 and 2021. The Company’s policy is to recognize transfers between levels as of the end of the reporting period. Transfers in and out of Level 1, Level 2, and Level 3 are recognized on the actual transfer date. There were no transfers between fair value hierarchy levels during the three and the six months ended June 30, 2022 and 2021. Further details on the methods used to estimate the fair value of each class of financial instruments above are discussed below: Investment Debt Securities Available-for-Sale . The Company obtains fair value measurements for investment securities from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information, and the investment’s terms and conditions, among other things. Vendors chosen by the Company are widely recognized vendors whose evaluations support the pricing functions of financial institutions, investment and mutual funds, and portfolio managers. If needed, a broker may be utilized to determine the reported fair value of investment securities. Loans Held for Sale. Fair value measurements for residential mortgage loans held for sale are obtained from an independent pricing service. The fair value measurements consider observable data that may include binding contracts or quotes or bids from third party investors as well as loan level pricing adjustments. Commercial and agricultural loans held for sale are derived from quotes or bids from third party investors. Interest Rate Swap Contracts. Fair values for derivative interest rate swap contracts are based upon the estimated amounts to settle the contracts considering current interest rates and are calculated using discounted cash flows that are observable or that can be corroborated by observable market data. The inputs used to determine fair value include the three-month LIBOR forward curve to estimate variable rate cash inflows and the Secured Overnight Financing Rate to estimate the discount rate. The estimated variable rate cash inflows are compared to the fixed rate outflows and such difference is discounted to a present value to estimate the fair value of the interest rate swaps. The change in the value of derivative assets attributable to basis risk, or the risk that offsetting investments in a hedging strategy will not experience price changes in entirely opposite directions, was not significant in the reported periods. The Company also obtains and compares the reasonableness of the pricing from an independent third party. For purposes of potential valuation adjustments to our derivative positions, we evaluate both our credit risk and the credit risk of our counterparties as well as ours. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods. Interest Rate Lock Commitments. Fair value measurements for interest rate lock commitments are obtained from an independent pricing service. The fair value measurements consider observable data that may include prices available from secondary market investors taking into consideration various characteristics of the loan, including the loan amount, interest rate, value of the servicing, and loan to value ratio, among other things. Observable data is then adjusted to reflect changes in interest rates, the Company’s estimated pull-through rate, and estimated direct costs necessary to complete the commitment into a closed loan net of origination, and processing fees collected from the borrower. Forward Loan Sales Contracts. The fair value measurements for forward loan sales contracts are obtained from an independent pricing service. The fair value measurements consider observable data that includes sales of similar loans.
Recent Authoritative Accounting Guidance	Recent Authoritative Accounting Guidance ASU 2020-04, “Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Accounting.” In March 2020, the FASB issued ASU 2020-04, which provides temporary exceptions that are optional for applying GAAP to loan and lease agreements, derivative contracts, and other transactions affected by the anticipated transition away from LIBOR toward new interest rate benchmarks. For transactions that are modified because of reference rate reform and that meet certain scope guidance (i) modifications of loan agreements should be accounted for by prospectively adjusting the effective interest rate, with such modification considered to be "minor" so that any existing unamortized origination fees/costs will carry forward and continue to be amortized and (ii) modifications of lease agreements should be accounted for as a continuation of the existing agreement with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required for modifications will not be accounted for as separate contracts. ASU 2020-04 is effective March 12, 2020 through December 31, 2022. An entity may elect to apply ASU 2020-04 for contract modifications as of January 1, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic within the Codification, the amendments in this ASU must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company adopted certain elections related to cash flow hedges which did not have a significant impact on the Company’s financial position or results of operations. The Company is currently evaluating the impact of the adoption of other expedients in the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-01, “ Reference Rate Reform (Topic 848) ” In January 2021, the FASB issued ASU 2021-01, Reference Rate Reform Topic 848 , that clarifies certain exceptions that are optional in Topic 848 for contract modifications and hedge accounting and apply those exceptions to derivatives that are affected by the discounting transition. An entity may elect to apply the amendments in this ASU on a full retrospective basis as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or on a prospective basis to new modifications from any date within an interim period that includes or is subsequent to the date of the issuance of a final ASU. If an entity elects to apply any of the amendments in this ASU for an eligible hedging relationship, any adjustments as a result of those elections must be reflected as of the date the entity applies the election. The amendments in this ASU do not apply to contract modifications made, new hedging relationships entered into, or existing hedging relationships evaluated for effectiveness in periods after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that apply certain exceptions that are optional in which the accounting effects of the hedging activity are recorded through the end of the hedging relationship (including periods after December 31, 2022). The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-08, “ Business Combinations (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers ” In October 2021, the FASB issued ASU 2021-08, Business Combinations Topic 805, Accounting for Contract Assets and Contract Liabilities from Contracts with Customers , to address diversity in practice and inconsistency related to the accounting for revenue contracts with customers acquired in a business combination. The amendments require that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606 as if it had originated the contracts. The amendments also provide certain practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from revenue contracts in a business combination and applies to contract assets and contract liabilities from other contracts to which the provisions of Topic 606 apply. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption is permitted, including in any interim period, for public business entities for periods for which financial statements have not yet been issued, and for all other entities for periods for which financial statements have not yet been made available for issuance. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-01, “ Derivatives and Hedging (Topic 815), Fair Value Hedging—Portfolio Layer Method ” In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging Topic 815, Fair Value Hedging—Portfolio Layer Method that clarifies the accounting for and promotes consistency in the reporting of hedge basis adjustments applicable to both a single hedged layer and multiple hedged layers. The amendments allow nonprepayable financial assets also to be included in a closed portfolio hedged using the portfolio layer method. That expanded scope permits an entity to apply the same portfolio hedging method to both prepayable and nonprepayable financial assets, thereby allowing consistent accounting for similar hedges. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption in an interim period is permitted for public business entities, with the effect of adopting the amendments related to basis adjustments reflected as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-02, “ Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings and Vintage Disclosures ” In March 2022, the FASB issued ASU 2022-02, Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings (TDRs) and Vintage Disclosures that eliminate the accounting guidance for TDRs by creditors in Subtopic 310-40, Receivables—Troubled Debt Restructurings by Creditors, while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Rather than applying the recognition and measurement guidance for TDRs, an entity must apply the loan refinancing and restructuring guidance to determine whether a modification results in a new loan or a continuation of an existing loan. The amendment also requires an entity disclose current-period gross writeoffs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Entities should apply the amendments prospectively except for the transition method related to the recognition and measurement of TDRs, an entity has the option to apply a modified retrospective transition method, resulting in a cumulative-effect adjustment to retained earnings in the period of adoption. Early adoption of the amendments are permitted, including adoption in an interim period. If an entity elects to early adopt the amendments in an interim period, the guidance should be applied as of the beginning of the fiscal year that includes the interim period. An entity may elect to early adopt the amendments about TDRs and related disclosure enhancements separately from the amendments related to vintage disclosures. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations.

Accounting Changes and Error Co

Accounting Changes and Error Corrections (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Changes and Error Corrections [Abstract]
Recent Authoritative Accounting Guidance	Recent Authoritative Accounting Guidance ASU 2020-04, “Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Accounting.” In March 2020, the FASB issued ASU 2020-04, which provides temporary exceptions that are optional for applying GAAP to loan and lease agreements, derivative contracts, and other transactions affected by the anticipated transition away from LIBOR toward new interest rate benchmarks. For transactions that are modified because of reference rate reform and that meet certain scope guidance (i) modifications of loan agreements should be accounted for by prospectively adjusting the effective interest rate, with such modification considered to be "minor" so that any existing unamortized origination fees/costs will carry forward and continue to be amortized and (ii) modifications of lease agreements should be accounted for as a continuation of the existing agreement with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required for modifications will not be accounted for as separate contracts. ASU 2020-04 is effective March 12, 2020 through December 31, 2022. An entity may elect to apply ASU 2020-04 for contract modifications as of January 1, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic within the Codification, the amendments in this ASU must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company adopted certain elections related to cash flow hedges which did not have a significant impact on the Company’s financial position or results of operations. The Company is currently evaluating the impact of the adoption of other expedients in the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-01, “ Reference Rate Reform (Topic 848) ” In January 2021, the FASB issued ASU 2021-01, Reference Rate Reform Topic 848 , that clarifies certain exceptions that are optional in Topic 848 for contract modifications and hedge accounting and apply those exceptions to derivatives that are affected by the discounting transition. An entity may elect to apply the amendments in this ASU on a full retrospective basis as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or on a prospective basis to new modifications from any date within an interim period that includes or is subsequent to the date of the issuance of a final ASU. If an entity elects to apply any of the amendments in this ASU for an eligible hedging relationship, any adjustments as a result of those elections must be reflected as of the date the entity applies the election. The amendments in this ASU do not apply to contract modifications made, new hedging relationships entered into, or existing hedging relationships evaluated for effectiveness in periods after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that apply certain exceptions that are optional in which the accounting effects of the hedging activity are recorded through the end of the hedging relationship (including periods after December 31, 2022). The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2021-08, “ Business Combinations (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers ” In October 2021, the FASB issued ASU 2021-08, Business Combinations Topic 805, Accounting for Contract Assets and Contract Liabilities from Contracts with Customers , to address diversity in practice and inconsistency related to the accounting for revenue contracts with customers acquired in a business combination. The amendments require that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606 as if it had originated the contracts. The amendments also provide certain practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from revenue contracts in a business combination and applies to contract assets and contract liabilities from other contracts to which the provisions of Topic 606 apply. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption is permitted, including in any interim period, for public business entities for periods for which financial statements have not yet been issued, and for all other entities for periods for which financial statements have not yet been made available for issuance. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-01, “ Derivatives and Hedging (Topic 815), Fair Value Hedging—Portfolio Layer Method ” In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging Topic 815, Fair Value Hedging—Portfolio Layer Method that clarifies the accounting for and promotes consistency in the reporting of hedge basis adjustments applicable to both a single hedged layer and multiple hedged layers. The amendments allow nonprepayable financial assets also to be included in a closed portfolio hedged using the portfolio layer method. That expanded scope permits an entity to apply the same portfolio hedging method to both prepayable and nonprepayable financial assets, thereby allowing consistent accounting for similar hedges. The amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Entities should apply the amendments prospectively to business combinations that occur after the effective date. Early adoption in an interim period is permitted for public business entities, with the effect of adopting the amendments related to basis adjustments reflected as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations. ASU 2022-02, “ Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings and Vintage Disclosures ” In March 2022, the FASB issued ASU 2022-02, Financial Instruments—Credit Losses (Topic 326), Troubled Debt Restructurings (TDRs) and Vintage Disclosures that eliminate the accounting guidance for TDRs by creditors in Subtopic 310-40, Receivables—Troubled Debt Restructurings by Creditors, while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Rather than applying the recognition and measurement guidance for TDRs, an entity must apply the loan refinancing and restructuring guidance to determine whether a modification results in a new loan or a continuation of an existing loan. The amendment also requires an entity disclose current-period gross writeoffs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Entities should apply the amendments prospectively except for the transition method related to the recognition and measurement of TDRs, an entity has the option to apply a modified retrospective transition method, resulting in a cumulative-effect adjustment to retained earnings in the period of adoption. Early adoption of the amendments are permitted, including adoption in an interim period. If an entity elects to early adopt the amendments in an interim period, the guidance should be applied as of the beginning of the fiscal year that includes the interim period. An entity may elect to early adopt the amendments about TDRs and related disclosure enhancements separately from the amendments related to vintage disclosures. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position or results of operations.

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2022
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table provides the provisional purchase price allocation as of the acquisition date and the Great Western assets acquired and liabilities assumed at their estimated fair value as of the acquisition date as amended for measurement period adjustments as of June 30, 2022. We recorded the estimate of fair value based on initial valuations available at the acquisition date. The excess value of the consideration paid over the fair value of assets acquired and liabilities assumed was recorded as goodwill. The purchase price allocation resulted in provisional goodwill of $478.2 million, which is not deductible for income tax purposes. Goodwill resulting from the acquisition was allocated to the Company’s one operating segment, community banking, and consists largely of the synergies and economies of scale expected from combining the operations of Great Western and the Company. Due to the recent closing of the transaction, all amounts reported are provisional pending the review of valuations obtained from third parties and other necessary information in support of related fair value accounting. As of February 1, 2022 Assets acquired: Cash and cash equivalents $ 2,006.9 Investment securities 2,699.0 Securities purchased under agreement to resell 101.1 Loans held for sale 217.0 Loans held for investment 7,705.0 Allowance for credit losses (59.5) Premises and equipment, including right of use lease assets 144.9 Other real estate owned (“OREO”) 15.8 Company owned life insurance 186.6 Core deposit intangibles 50.1 Customer relationship intangible 22.8 Mortgage servicing rights 1.3 Deferred tax assets, net 63.6 Other assets 198.0 Total assets acquired 13,352.6 Liabilities assumed: Deposits 11,688.0 Securities sold under repurchase agreements 74.0 Accrued expenses and other liabilities 110.1 FHLB advances 122.9 Subordinated debt 36.4 Subordinated debentures held by subsidiary trusts 76.1 Total liabilities assumed 12,107.5 Net assets acquired $ 1,245.1 Consideration paid: Class A common stock 1,723.3 Total consideration paid (1) $ 1,723.3 Goodwill $ 478.2 (1) Includes $13 thousand of cash paid in lieu of fractional shares.
Business Combination, Separately Recognized Transactions	As of June 30, 2022, the Company recorded measurement period adjustments to the fair value marks as indicated in the table below. These adjustments resulted in a net decrease to goodwill of $37.8 million from the March 31, 2022 reported balances. The related impact to net income that would have been recognized in previous periods if the adjustments were recognized as of the acquisition date was not material to the consolidated financial statements. Asset adjustments: Loans held for sale $ 35.1 Loans held for investment (8.4) Allowance for credit losses 24.8 Premises and equipment 0.8 Core deposit intangibles 1.0 Deferred tax assets (12.5) Total asset adjustments $ 40.8 Liability adjustments: Accrued expenses and other liabilities $ 3.0 Total liability adjustments $ 3.0 Net adjustment to goodwill $ (37.8)
Financing Receivable, Purchased	The non-credit discount or premium, after the adjustment for the allowance for credit losses, is accreted to interest income using the interest method based on the effective interest rate determined after the adjustment for credit losses at the adoption date. Information regarding loans acquired at the acquisition date as amended for measurement period adjustments as of June 30, 2022 were as follows: (In millions) PCD loans: Unpaid principal balance $ 979.2 Principal amounts previously written off by GWB (238.7) Interest applied to principal by GWB (18.1) Adjusted unpaid principal balance 722.4 Credit discount (69.2) Discount attributable to other factors (29.9) Fair value 623.3 Allowance for credit losses 59.5 Amortized cost basis 682.8 Non-PCD loans: Unpaid principal balance 7,107.9 Credit discount (1) (76.5) Non-credit discount (9.2) Fair value 7,022.2 Amortized cost basis $ 7,705.0 (1) Represents the best estimate of the contractual cash flows not expected to be collected as of the acquisition date.
Schedule of Pro Forma Financial Information	The following table presents certain unaudited pro forma financial information for illustrative purposes only, for the three and the six month periods ended June 30, 2022 and 2021 as if GWB had been acquired on January 1, 2021. This unaudited pro forma information combines the historical results of GWB with the Company’s consolidated historical results and includes certain adjustments reflecting the estimated impact of certain fair value adjustments for the respective periods. The pro forma information is not indicative of what would have occurred had the acquisition occurred at the beginning of the year prior to the acquisition. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value, cost savings, or business synergies. As a result, actual amounts would have differed from the unaudited pro forma information presented, and the differences could be significant. Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Total revenues $ 300.7 $ 291.8 $ 569.6 $ 613.4 Net income $ 101.1 $ 144.6 $ 177.5 $ 66.4 Earnings per common share (Basic) $ 0.93 $ 1.33 $ 1.76 $ 0.61 Earnings per common share (Diluted) $ 0.93 $ 1.33 $ 1.76 $ 0.61

Goodwill and Core Deposit Int_2

Goodwill and Core Deposit Intangibles (Tables)	6 Months Ended
	Jun. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table details changes in the recorded amount of goodwill as of the dates indicated: As of June 30, June 30, 2022 December 31, 2021 Net carrying value at beginning of the period $ 621.6 $ 621.6 Provisional additions to goodwill from acquisition 478.2 — Net carrying value at end of period $ 1,099.8 $ 621.6
Schedule of Intangibles	Other intangible assets are comprised of core deposit intangibles (“CDI”) and other customer relationship intangibles (“OCRI”) and amounted to the following at June 30, 2022 and December 31, 2021: As of June 30, 2022 CDI OCRI Total Gross other intangible assets, at beginning of the period $ 106.0 $ — $ 106.0 Provisional amounts established through acquisition 50.1 22.8 72.9 Reductions due to sale of health savings accounts (1.4) — (1.4) Accumulated amortization (71.6) (0.8) (72.4) Net other intangible assets, end of period $ 83.1 $ 22.0 $ 105.1 December 31, 2021 Gross other intangible assets, at beginning of the period $ 106.0 $ — $ 106.0 Accumulated amortization (64.7) — (64.7) Net other intangible assets, end of period $ 41.3 $ — $ 41.3
Schedule of Future Amortization Expense	The following table provides the estimated aggregate future amortization expense of other intangible assets: Years Ending December 31, CDI OCRI Total 2022 remaining $ 7.2 $ 0.9 $ 8.1 2023 13.7 1.9 15.6 2024 12.7 1.9 14.6 2025 11.8 1.9 13.7 2026 10.9 1.9 12.8 Thereafter 26.8 13.5 40.3 Total $ 83.1 $ 22.0 $ 105.1

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Approximate Fair Values of Investment Securities	The amortized cost and the approximate fair values of investment securities are summarized as follows: June 30, 2022 Amortized Gross Gross Estimated Available-for-Sale: U.S. Treasury notes $ 871.0 $ 1.4 $ (62.6) $ 809.8 State, county, and municipal securities 325.0 0.1 (42.9) 282.2 Obligations of U.S. government agencies 235.3 — (9.4) 225.9 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 5,054.7 2.0 (241.3) 4,815.4 Private mortgage-backed securities 278.1 — (25.1) 253.0 Collateralized loan obligations 1,145.7 — (51.7) 1,094.0 Corporate securities 284.0 — (23.2) 260.8 Total $ 8,193.8 $ 3.5 $ (456.2) $ 7,741.1 June 30, 2022 Amortized Allowance for Credit Losses Net Carrying Amount Gross Gross Estimated Held-to-Maturity: U.S. Treasury notes $ 296.7 $ — $ 296.7 $ — $ (3.6) $ 293.1 State, county, and municipal securities 186.6 (0.1) 186.5 0.5 (24.0) 163.0 Obligations of U.S. government agencies 328.1 — 328.1 — (28.9) 299.2 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations (1) 2,236.0 — 2,236.0 — (208.7) 2,027.3 Corporate securities 84.2 (1.5) 82.7 — (4.8) 77.9 Total $ 3,131.6 $ (1.6) $ 3,130.0 $ 0.5 $ (270.0) $ 2,860.5 (1) Amortized cost presented above include $21.1 million of unamortized losses and $15.9 million of unamortized gains in U.S. agency residential and commercial mortgage-backed securities and collateralized mortgage obligations related to the 2021 and 2022 transfer of securities from available-for-sale to held-to-maturity. December 31, 2021 Amortized Gross Gross Estimated Available-for-Sale: U.S. Treasury notes $ 697.6 $ — $ (12.9) $ 684.7 State, county, and municipal securities 434.7 2.1 (9.3) 427.5 Obligations of U.S. government agencies 356.0 0.1 (9.2) 346.9 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 2,027.3 14.1 (23.3) 2,018.1 Private mortgage-backed securities 174.4 0.1 (1.1) 173.4 Collateralized loan obligation 898.2 1.2 — 899.4 Corporate securities 271.1 3.0 (3.6) 270.5 Total $ 4,859.3 $ 20.6 $ (59.4) $ 4,820.5 December 31, 2021 Amortized Allowance for Credit Losses Net Carrying Amount Gross Gross Estimated Held-to-Maturity: State, county, and municipal securities $ 67.6 $ — $ 67.6 $ 2.0 $ (0.4) $ 69.2 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations (1) 1,609.0 — 1,609.0 13.2 (35.3) 1,586.9 Corporate securities 11.0 — 11.0 0.4 — 11.4 Total $ 1,687.6 $ — $ 1,687.6 $ 15.6 $ (35.7) $ 1,667.5 (1) Amortized cost presented above include $20.1 million of unamortized gains in U.S. agency residential and commercial mortgage-backed securities and collateralized mortgage obligations related to the 2021 transfer of securities from available-for-sale to held-to-maturity.
Gross Unrealized Losses and Fair Values of Investment Securities	The following tables show the gross unrealized losses and fair values of investment securities, aggregated by investment category, and the length of time individual investment securities have been in an unrealized loss position as of June 30, 2022 and December 31, 2021. Less than 12 Months 12 Months or More Total June 30, 2022 Fair Gross Fair Gross Fair Gross Available-for-Sale: U.S. Treasury notes $ 177.6 $ (23.0) $ 458.1 $ (39.6) $ 635.7 $ (62.6) State, county, and municipal securities 136.7 (15.8) 123.3 (27.1) 260.0 (42.9) Obligations of U.S. government agencies 191.7 (6.5) 28.1 (2.9) 219.8 (9.4) U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 3,838.2 (159.7) 621.8 (81.6) 4,460.0 (241.3) Private mortgage-backed securities 242.9 (24.2) 10.1 (0.9) 253.0 (25.1) Collateralized loan obligations 1,094.0 (51.7) — — 1,094.0 (51.7) Corporate securities 149.4 (6.2) 90.5 (17.0) 239.9 (23.2) Total $ 5,830.5 $ (287.1) $ 1,331.9 $ (169.1) $ 7,162.4 $ (456.2) Less than 12 Months 12 Months or More Total December 31, 2021 Fair Gross Fair Gross Fair Gross Available-for-Sale: U.S. Treasury notes $ 684.7 $ (12.9) $ — $ — $ 684.7 $ (12.9) State, county, and municipal securities 278.7 (9.1) 5.0 (0.2) 283.7 (9.3) Obligations of U.S. government agencies 297.0 (8.9) 16.4 (0.3) 313.4 (9.2) U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations 1,262.8 (23.0) 26.4 (0.3) 1,289.2 (23.3) Private mortgage-backed securities 127.2 (1.1) — — 127.2 (1.1) Corporate securities 109.9 (3.3) 20.9 (0.3) 130.8 (3.6) Total $ 2,760.3 $ (58.3) $ 68.7 $ (1.1) $ 2,829.0 $ (59.4)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	The following table presents the activity in the allowance for credit losses related to held-to-maturity securities classified as corporate and state, county, and municipal securities: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 1.6 $ — $ — $ — Provision for credit loss expense — — 1.6 — Ending balance of allowance for credit losses $ 1.6 $ — $ 1.6 $ —
Debt Securities, Held-to-maturity, Credit Quality Indicator	The following table summarizes the credit quality indicators of held-to-maturity securities at amortized cost for the periods indicated: June 30, 2022 AAA AA A BBB Not Rated Total U.S. Treasury notes $ 296.7 $ — $ — $ — $ — $ 296.7 State, county, and municipal securities 69.4 95.1 12.0 — 10.1 186.6 Obligations of U.S. government agencies 328.1 — — — — 328.1 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations FNMA/FHLMC 1,903.2 — — — — 1,903.2 GNMA 332.8 — — — — 332.8 Corporate securities — — 4.0 75.2 5.0 84.2 Total $ 2,930.2 $ 95.1 $ 16.0 $ 75.2 $ 15.1 $ 3,131.6 December 31, 2021 AAA AA A BBB Not Rated Total State, county, and municipal securities $ 17.2 $ 31.6 $ 14.7 $ — $ 4.1 $ 67.6 U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations FNMA/FHLMC 1,439.1 — — — — 1,439.1 GNMA 169.9 — — — — 169.9 Corporate securities — — 4.0 7.0 — 11.0 Total $ 1,626.2 $ 31.6 $ 18.7 $ 7.0 $ 4.1 $ 1,687.6
Maturities of Investment Securities	Maturities of mortgage-backed securities have been adjusted to reflect shorter maturities based upon estimated prepayments of principal. All other investment securities maturities are shown at contractual maturity dates. Available-for-Sale Held-to-Maturity June 30, 2022 Amortized Estimated Amortized Estimated Within one year $ 84.8 $ 84.4 $ 10.1 $ 10.1 After one year but within five years 1,566.4 1,507.7 375.0 367.9 After five years but within ten years 1,865.4 1,738.6 784.5 718.4 After ten years 4,677.2 4,410.4 1,962.0 1,764.1 Total $ 8,193.8 $ 7,741.1 $ 3,131.6 $ 2,860.5

Loans Held for Sale (Tables)

Loans Held for Sale (Tables)	6 Months Ended
	Jun. 30, 2022
Receivables [Abstract]
Loans Held For Sale (Table)	The following table presents loans held for sale by segment for the dates indicated: June 30, December 31, Loans Held for Sale: Agricultural $ 113.3 $ — Residential real estate 14.1 30.1 Total loans held for sale $ 127.4 $ 30.1

Loans Held for Investment (Tabl

Loans Held for Investment (Tables)	6 Months Ended
	Jun. 30, 2022
Receivables [Abstract]
Schedule of Loans by Class	The following table presents loans by segment as of the dates indicated: June 30, December 31, Real estate loans: Commercial $ 7,857.7 $ 3,971.5 Construction loans: Land acquisition & development 355.7 247.8 Residential 444.8 262.0 Commercial 959.0 498.0 Total construction loans 1,759.5 1,007.8 Residential 2,060.4 1,538.2 Agricultural 821.5 213.9 Total real estate loans 12,499.1 6,731.4 Consumer loans: Indirect 733.9 737.6 Direct and advance lines 157.3 129.2 Credit card 74.8 64.9 Total consumer loans 966.0 931.7 Commercial 3,036.0 1,475.5 Agricultural 672.0 203.9 Other, including overdrafts — 1.5 Loans held for investment 17,173.1 9,344.0 Deferred loan fees and costs (10.6) (12.3) Loans held for investment, net of deferred fees and costs 17,162.5 9,331.7 Allowance for credit losses (220.4) (122.3) Net loans held for investment $ 16,942.1 $ 9,209.4
Schedule of Allowance for Loan Losses by Portfolio Segment	The following tables represent, by loan portfolio segment, the activity in the allowance for credit losses for loans held for investment: Three Months Ended June 30, 2022 Beginning Balance Provisional ACL Recorded for PCD loans Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 45.2 $ (6.9) $ (8.8) $ — $ — $ 29.5 Owner occupied 25.2 — 1.4 — — 26.6 Multi-family 54.6 (19.0) (2.9) — 0.7 33.4 Total commercial real estate 125.0 (25.9) (10.3) — 0.7 89.5 Construction: Land acquisition & development 0.5 — 0.2 — 0.1 0.8 Residential construction 3.3 — 0.1 — — 3.4 Commercial construction 10.2 — 4.7 — — 14.9 Total construction 14.0 — 5.0 — 0.1 19.1 Residential real estate: Residential 1-4 family 18.7 — (0.7) — 0.2 18.2 Home equity and HELOC 1.4 — (0.1) — 0.2 1.5 Total residential real estate 20.1 — (0.8) — 0.4 19.7 Agricultural real estate 10.5 — (5.1) (0.1) 0.1 5.4 Total real estate 169.6 (25.9) (11.2) (0.1) 1.3 133.7 Consumer: Indirect 13.5 — (0.4) (0.8) 0.8 13.1 Direct and advance lines 4.6 — 0.5 (0.6) 0.5 5.0 Credit card 2.3 — 0.7 (0.9) 0.1 2.2 Total consumer 20.4 — 0.8 (2.3) 1.4 20.3 Commercial: Commercial and floor plans 52.9 — 1.9 (1.1) 0.4 54.1 Commercial purpose secured by 1-4 family 5.0 — 0.4 — 0.1 5.5 Credit card 0.3 — 0.1 (0.1) — 0.3 Total commercial 58.2 — 2.4 (1.2) 0.5 59.9 Agricultural: Agricultural (2) (1.0) 1.1 6.3 (0.1) 0.2 6.5 Total agricultural (1.0) 1.1 6.3 (0.1) 0.2 6.5 Total allowance for credit losses $ 247.2 $ (24.8) $ (1.7) $ (3.7) $ 3.4 $ 220.4 (1) Amounts presented exclude the allowance for credit losses related to unfunded commitments. These amounts are included in Note “Financial Instruments with Off-Balance Sheet Risk” and the allowance for credit losses related to investment securities which are included in Note “Investment Securities” included in this report. (2) The agricultural ACL beginning balance reflects loan reclassifications to conform the March 31, 2022 loan classifications to June 30, 2022 which were offset by additional provisional ACL as of June 30, 2022. Six Months Ended June 30, 2022 Beginning Balance Provisional ACL Recorded for PCD loans Provision for (reversal of) Credit Losses (2) Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 17.3 $ 17.2 $ (2.1) $ (2.9) $ — $ 29.5 Owner occupied 13.3 9.5 6.0 (2.2) — 26.6 Multi-family 13.3 10.9 8.5 — 0.7 33.4 Total commercial real estate 43.9 37.6 12.4 (5.1) 0.7 89.5 Construction: Land acquisition & development 0.5 3.4 (0.6) (2.7) 0.2 0.8 Residential construction 2.4 — 1.0 — — 3.4 Commercial construction 6.0 0.2 8.7 — — 14.9 Total construction 8.9 3.6 9.1 (2.7) 0.2 19.1 Residential real estate: Residential 1-4 family 13.4 0.1 4.5 (0.1) 0.3 18.2 Home equity and HELOC 1.2 — — — 0.3 1.5 Total residential real estate 14.6 0.1 4.5 (0.1) 0.6 19.7 Agricultural real estate 1.9 2.3 1.3 (0.2) 0.1 5.4 Total real estate 69.3 43.6 27.3 (8.1) 1.6 133.7 Consumer: Indirect 14.3 — (0.7) (1.7) 1.2 13.1 Direct and advance lines 4.6 — 0.4 (1.4) 1.4 5.0 Credit card 2.2 — 1.3 (1.5) 0.2 2.2 Total consumer 21.1 — 1.0 (4.6) 2.8 20.3 Commercial: Commercial and floor plans 27.1 11.2 20.3 (5.3) 0.8 54.1 Commercial purpose secured by 1-4 family 4.4 0.2 0.8 — 0.1 5.5 Credit card 0.1 — 0.4 (0.2) — 0.3 Total commercial 31.6 11.4 21.5 (5.5) 0.9 59.9 Agricultural: Agricultural 0.3 4.5 5.8 (5.4) 1.3 6.5 Total agricultural 0.3 4.5 5.8 (5.4) 1.3 6.5 Total allowance for credit losses $ 122.3 $ 59.5 $ 55.6 $ (23.6) $ 6.6 $ 220.4 (1) Amounts presented are exclusive of the allowance for credit losses related to unfunded commitments which are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report. (2) Amounts include $68.3 million related to the acquired GWB non-PCD loans. Three Months Ended June 30, 2021 Beginning Balance Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 23.0 $ (0.2) $ — $ 0.1 $ 22.9 Owner occupied 17.4 1.4 (2.2) — 16.6 Multi-family 11.8 (0.2) — — 11.6 Total commercial real estate 52.2 1.0 (2.2) 0.1 51.1 Construction: Land acquisition & development 1.2 (0.4) (0.1) 0.3 1.0 Residential construction 1.4 0.2 (0.1) — 1.5 Commercial construction 7.2 0.9 (0.1) — 8.0 Total construction 9.8 0.7 (0.3) 0.3 10.5 Residential real estate: Residential 1-4 family 11.5 1.9 — — 13.4 Home equity and HELOC 1.4 (0.1) — 0.1 1.4 Total residential real estate 12.9 1.8 — 0.1 14.8 Agricultural real estate 2.8 0.2 — — 3.0 Total real estate 77.7 3.7 (2.5) 0.5 79.4 Consumer: Indirect 16.0 (0.2) (0.8) 0.8 15.8 Direct and advance lines 4.8 — (0.4) 0.2 4.6 Credit card 1.5 0.3 (0.4) 0.2 1.6 Total consumer 22.3 0.1 (1.6) 1.2 22.0 Commercial: Commercial and floor plans 31.0 (3.4) (0.3) 1.7 29.0 Commercial purpose secured by 1-4 family 4.7 (0.4) (0.1) 0.2 4.4 Credit card 0.3 — (0.1) 0.1 0.3 Total commercial 36.0 (3.8) (0.5) 2.0 33.7 Agricultural: Agricultural 0.6 — (0.2) — 0.4 Total agricultural 0.6 — (0.2) — 0.4 Total allowance for credit losses $ 136.6 $ — $ (4.8) $ 3.7 $ 135.5 (1) Amounts presented exclude the allowance for credit losses related to unfunded commitments. These amounts are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report. Six Months Ended June 30, 2021 Beginning Balance Provision for (reversal of) Credit Losses Loans Charged-Off Recoveries Collected Ending Balance Allowance for credit losses (1) Real estate: Commercial real estate: Non-owner occupied $ 25.5 $ (2.7) $ — $ 0.1 $ 22.9 Owner occupied 18.3 0.6 (2.3) — 16.6 Multi-family 11.0 0.6 — — 11.6 Total commercial real estate 54.8 (1.5) (2.3) 0.1 51.1 Construction: Land acquisition & development 1.3 (0.6) (0.1) 0.4 1.0 Residential construction 1.6 — (0.1) — 1.5 Commercial construction 7.3 0.7 (0.1) 0.1 8.0 Total construction 10.2 0.1 (0.3) 0.5 10.5 Residential real estate: Residential 1-4 family 11.4 2.0 — — 13.4 Home equity and HELOC 1.4 (0.1) (0.1) 0.2 1.4 Total residential real estate 12.8 1.9 (0.1) 0.2 14.8 Agricultural real estate 2.7 0.3 — — 3.0 Total real estate 80.5 0.8 (2.7) 0.8 79.4 Consumer: Indirect 16.7 (0.2) (2.1) 1.4 15.8 Direct and advance lines 4.6 0.7 (1.2) 0.5 4.6 Credit card 2.6 (0.4) (1.0) 0.4 1.6 Total consumer 23.9 0.1 (4.3) 2.3 22.0 Commercial: Commercial and floor plans 34.2 (5.2) (2.1) 2.1 29.0 Commercial purpose secured by 1-4 family 4.7 (0.6) (0.1) 0.4 4.4 Credit card 0.3 0.2 (0.3) 0.1 0.3 Total commercial 39.2 (5.6) (2.5) 2.6 33.7 Agricultural: Agricultural 0.7 (0.1) (0.2) — 0.4 Total agricultural 0.7 (0.1) (0.2) — 0.4 Total allowance for credit losses $ 144.3 $ (4.8) $ (9.7) $ 5.7 $ 135.5 (1) Amounts presented are exclusive of the allowance for credit losses related to unfunded commitments which are included in Note “Financial Instruments with Off-Balance Sheet Risk” included in this report.
Schedule of Recorded Investment in Impaired Loans	The following tables present the amortized cost basis of collateral-dependent loans by class of loans as of the dates indicated: Collateral Type As of June 30, 2022 Business Assets Real Property Other Total Real estate $ 1.2 $ 63.6 $ — $ 64.8 Commercial 4.6 5.6 — 10.2 Agricultural — 10.5 — 10.5 Total collateral-dependent $ 5.8 $ 79.7 $ — $ 85.5 Collateral Type As of December 31, 2021 Business Assets Real Property Other Total Real estate $ 1.2 $ 7.0 $ — $ 8.2 Commercial 1.8 1.0 — 2.8 Agricultural — 0.7 — 0.7 Total collateral-dependent $ 3.0 $ 8.7 $ — $ 11.7
Schedule of Recorded Investment in Past Due Loans by Class	Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans classified in the following table as greater than 90 days past due continue to accrue interest. The following tables present the contractual aging of the Company’s recorded amortized cost basis in loans by portfolio as of the dates indicated. Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of June 30, 2022 Past Due Past Due Past Due Past Due Loans Loans (1) Loans Real estate Commercial $ 5.1 $ 2.1 $ 0.7 $ 7.9 $ 7,820.1 $ 29.7 $ 7,857.7 Construction: Land acquisition & development 0.7 0.1 — 0.8 350.8 4.1 355.7 Residential 1.0 0.4 — 1.4 443.4 — 444.8 Commercial 10.7 — — 10.7 948.3 — 959.0 Total construction loans 12.4 0.5 — 12.9 1,742.5 4.1 1,759.5 Residential 3.2 2.1 0.4 5.7 2,049.7 5.0 2,060.4 Agricultural 2.1 — 0.3 2.4 781.2 37.9 821.5 Total real estate loans 22.8 4.7 1.4 28.9 12,393.5 76.7 12,499.1 Consumer: Indirect consumer 5.3 1.4 0.2 6.9 725.2 1.8 733.9 Other consumer 0.6 0.2 — 0.8 156.3 0.2 157.3 Credit card 0.6 0.2 0.3 1.1 73.7 — 74.8 Total consumer loans 6.5 1.8 0.5 8.8 955.2 2.0 966.0 Commercial 8.4 2.1 1.0 11.5 3,010.6 13.9 3,036.0 Agricultural 10.0 0.1 — 10.1 647.5 14.4 672.0 Loans held for investment $ 47.7 $ 8.7 $ 2.9 $ 59.3 $ 17,006.8 $ 107.0 $ 17,173.1 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2021 Past Due Past Due Past Due Past Due Loans Loans (1) Loans Real estate Commercial $ 1.1 $ 1.0 $ 0.6 $ 2.7 $ 3,960.8 $ 8.0 $ 3,971.5 Construction: Land acquisition & development 0.2 — — 0.2 246.9 0.7 247.8 Residential 4.2 — — 4.2 257.8 — 262.0 Commercial — — — — 498.0 — 498.0 Total construction loans 4.4 — — 4.4 1,002.7 0.7 1,007.8 Residential 3.0 0.8 0.1 3.9 1,531.4 2.9 1,538.2 Agricultural 1.9 0.2 — 2.1 206.9 4.9 213.9 Total real estate loans 10.4 2.0 0.7 13.1 6,701.8 16.5 6,731.4 Consumer: Indirect consumer 5.1 1.4 0.4 6.9 729.0 1.7 737.6 Other consumer 0.5 0.2 0.1 0.8 128.3 0.1 129.2 Credit card 0.6 0.2 0.5 1.3 63.6 — 64.9 Total consumer loans 6.2 1.8 1.0 9.0 920.9 1.8 931.7 Commercial 4.9 0.7 1.1 6.7 1,463.8 5.0 1,475.5 Agricultural 0.7 — — 0.7 201.6 1.6 203.9 Other, including overdrafts — — — — 1.5 — 1.5 Loans held for investment $ 22.2 $ 4.5 $ 2.8 $ 29.5 $ 9,289.6 $ 24.9 $ 9,344.0 (1) As of June 30, 2022 and December 31, 2021, none of our non-accrual loans were earning interest income. Additionally, no material interest income was recognized on non-accrual loans during the three and the six months ended June 30, 2022 and 2021, respectively. There were no material reversals of accrued interest at June 30, 2022 and 2021.
Financing Receivable, Troubled Debt Restructuring	The Company had $6.4 million and $23.6 million of new troubled debt restructurings during the three and the six months ended June 30, 2022, respectively. Number of Notes Type of Concession Principal Balance at Restructure Three Months Ended June 30, 2022 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 1 $ — $ — $ — $ 0.2 $ 0.2 Residential real estate 1 — 0.1 — — 0.1 Commercial 1 — — — 0.2 0.2 Agricultural 1 — — — 5.9 5.9 Total loans restructured during period 4 $ — $ 0.1 $ — $ 6.3 $ 6.4 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories . Number of Notes Type of Concession Principal Balance at Restructure Six Months Ended June 30, 2022 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 3 $ 3.2 $ 4.2 $ — $ 0.2 $ 7.6 Residential real estate 2 — 0.6 — — 0.6 Agriculture real estate 1 — 8.9 — — 8.9 Commercial 2 — — — 0.6 0.6 Agriculture 1 — — — 5.9 5.9 Total loans restructured during period 9 $ 3.2 $ 13.7 $ — $ 6.7 $ 23.6 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories.
Schedule of Acquired Loans with Credit Impairment	The following table reconciles the par value, or initial amortized cost, of PCD loans acquired in the GWB acquisition as of the date of the acquisition with the purchase price (or initial fair value of the loans) as amended for measurement period adjustments as of June 30, 2022: Purchase price (initial fair value) $ 623.3 Allowance for credit losses (1) 298.2 Discount attributable to other factors (2) 57.7 Par value (unpaid principal balance) $ 979.2 (1) For acquired PCD loans, an allowance of $298.2 million was required with a corresponding increase to the amortized cost basis as of the acquisition date. For PCD loans where all or a portion of the loan balance had been previously written-off by GWB, or would be subject to write-off under the Company’s charge-off policy, a CECL allowance of $238.7 million, included as part of the grossed-up loan balance at acquisition was immediately written-off. The net impact to the allowance for PCD assets on the acquisition date was $59.5 million. (2) Non-credit discount includes the difference between the amortized cost basis and the unpaid principal balance of $39.6 million established on GWB PCD loans acquired and interest applied to principal of $18.1 million.
Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator	The Company evaluates the credit quality and loan performance for the allowance for credit loan losses of the following segments based on the aforementioned risk scale for the periods indicated: June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Commercial real estate non-owner occupied: Pass $ 458.6 $ 817.2 $ 677.9 $ 536.0 $ 251.2 $ 641.7 $ 30.4 $ 3,413.0 Special mention 6.1 25.0 1.9 18.0 33.8 24.5 — 109.3 Substandard 3.2 12.8 25.0 17.7 31.6 32.0 — 122.3 Doubtful 0.3 — — 1.6 1.8 — — 3.7 Total $ 468.2 $ 855.0 $ 704.8 $ 573.3 $ 318.4 $ 698.2 $ 30.4 $ 3,648.3 Commercial real estate owner occupied: Pass $ 438.6 $ 793.8 $ 564.2 $ 307.8 $ 239.7 $ 887.2 $ 25.1 $ 3,256.4 Special mention 3.0 5.6 3.0 7.1 2.1 12.7 0.3 33.8 Substandard 10.3 2.9 3.0 5.2 4.3 26.8 0.4 52.9 Doubtful — 2.9 — — 9.4 2.0 — 14.3 Total $ 451.9 $ 805.2 $ 570.2 $ 320.1 $ 255.5 $ 928.7 $ 25.8 $ 3,357.4 Commercial multi-family: Pass $ 152.3 $ 212.8 $ 185.3 $ 54.0 $ 36.5 $ 122.7 $ 3.2 $ 766.8 Substandard — — 37.5 1.2 46.2 0.3 — 85.2 Total $ 152.3 $ 212.8 $ 222.8 $ 55.2 $ 82.7 $ 123.0 $ 3.2 $ 852.0 Land, acquisition and development: Pass $ 79.1 $ 151.9 $ 33.8 $ 26.1 $ 15.2 $ 31.7 $ 12.7 $ 350.5 Special mention — — — — 0.2 0.3 — 0.5 Substandard — 0.7 0.2 — — 0.6 — 1.5 Doubtful — 3.2 — — — — — 3.2 Total $ 79.1 $ 155.8 $ 34.0 $ 26.1 $ 15.4 $ 32.6 $ 12.7 $ 355.7 Residential construction: Pass $ 73.1 $ 138.8 $ 0.4 $ 9.7 $ 0.8 $ 6.2 $ 215.4 $ 444.4 Substandard — — — — — 0.4 — 0.4 Total $ 73.1 $ 138.8 $ 0.4 $ 9.7 $ 0.8 $ 6.6 $ 215.4 $ 444.8 Commercial construction: Pass $ 198.0 $ 432.0 $ 187.6 $ 87.2 $ 1.9 $ — $ 7.5 $ 914.2 Special mention — — 23.1 — — — — 23.1 Substandard — — — 21.7 — — — 21.7 Total $ 198.0 $ 432.0 $ 210.7 $ 108.9 $ 1.9 $ — $ 7.5 $ 959.0 Agricultural real estate: Pass $ 112.6 $ 182.2 $ 122.2 $ 70.0 $ 53.9 $ 134.1 $ 29.8 $ 704.8 Special mention 1.5 2.5 2.3 1.8 9.7 5.9 9.9 33.6 Substandard 3.3 17.6 4.0 3.2 22.0 13.7 12.6 76.4 Doubtful — 0.9 3.1 0.8 — 1.9 — 6.7 Total $ 117.4 $ 203.2 $ 131.6 $ 75.8 $ 85.6 $ 155.6 $ 52.3 $ 821.5 Commercial and floor plans: Pass $ 318.5 $ 447.6 $ 256.9 $ 151.3 $ 149.1 $ 202.6 $ 821.7 $ 2,347.7 Special mention 6.6 7.1 2.5 4.1 2.3 6.1 22.4 51.1 Substandard 13.5 1.5 3.4 2.6 3.6 8.1 11.6 44.3 Doubtful — 4.7 0.2 — — 1.6 — 6.5 Total $ 338.6 $ 460.9 $ 263.0 $ 158.0 $ 155.0 $ 218.4 $ 855.7 $ 2,449.6 June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Commercial purpose secured by 1-4 family: Pass $ 106.5 $ 147.2 $ 69.9 $ 32.7 $ 32.4 $ 47.6 $ 25.0 $ 461.3 Special mention 0.2 0.4 0.6 0.6 1.9 0.6 — 4.3 Substandard 0.4 1.3 1.2 0.3 0.6 1.3 0.1 5.2 Doubtful — 0.2 — — — — — 0.2 Total $ 107.1 $ 149.1 $ 71.7 $ 33.6 $ 34.9 $ 49.5 $ 25.1 $ 471.0 Agricultural: Pass $ 103.1 $ 91.1 $ 37.2 $ 13.4 $ 10.6 $ 1.2 $ 343.8 $ 600.4 Special mention 3.1 2.2 0.6 1.3 0.7 0.3 10.9 19.1 Substandard 22.8 6.9 5.1 0.9 1.8 0.7 4.3 42.5 Doubtful — 4.6 — — 2.5 0.9 — 8.0 Total $ 129.0 $ 104.8 $ 42.9 $ 15.6 $ 15.6 $ 3.1 $ 359.0 $ 670.0 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Commercial real estate non-owner occupied: Pass $ 507.9 $ 452.2 $ 237.9 $ 150.4 $ 76.3 $ 409.0 $ 15.3 $ 1,849.0 Special mention 0.2 3.1 2.1 — — 3.6 — 9.0 Substandard 3.9 15.3 2.3 0.7 1.0 12.4 — 35.6 Total $ 512.0 $ 470.6 $ 242.3 $ 151.1 $ 77.3 $ 425.0 $ 15.3 $ 1,893.6 Commercial real estate owner occupied: Pass $ 452.7 $ 314.9 $ 235.0 $ 151.0 $ 94.5 $ 322.5 $ 14.2 $ 1,584.8 Special mention 1.3 3.2 1.5 7.4 3.5 13.8 — 30.7 Substandard 3.8 4.3 4.7 5.4 2.7 20.3 — 41.2 Total $ 457.8 $ 322.4 $ 241.2 $ 163.8 $ 100.7 $ 356.6 $ 14.2 $ 1,656.7 Commercial multi-family: Pass $ 129.1 $ 118.6 $ 43.9 $ 15.4 $ 36.0 $ 76.7 $ 1.5 $ 421.2 Total $ 129.1 $ 118.6 $ 43.9 $ 15.4 $ 36.0 $ 76.7 $ 1.5 $ 421.2 Land, acquisition and development: Pass $ 113.0 $ 41.5 $ 34.2 $ 14.8 $ 19.8 $ 20.8 $ 1.2 $ 245.3 Special mention — 0.1 — — 0.1 0.3 — 0.5 Substandard 0.8 0.2 — 0.6 0.3 0.1 — 2.0 Total $ 113.8 $ 41.8 $ 34.2 $ 15.4 $ 20.2 $ 21.2 $ 1.2 $ 247.8 Residential construction: Pass $ 112.4 $ 7.0 $ 13.7 $ 0.9 $ — $ — $ 127.2 $ 261.2 Substandard — 0.4 — — 0.4 — — 0.8 Total $ 112.4 $ 7.4 $ 13.7 $ 0.9 $ 0.4 $ — $ 127.2 $ 262.0 Commercial construction: Pass $ 209.7 $ 141.4 $ 118.8 $ 27.6 $ — $ 0.5 $ — $ 498.0 Total $ 209.7 $ 141.4 $ 118.8 $ 27.6 $ — $ 0.5 $ — $ 498.0 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Agricultural real estate: Pass $ 58.3 $ 36.9 $ 35.1 $ 22.6 $ 11.8 $ 28.1 $ 4.9 $ 197.7 Special mention 0.1 1.3 1.2 0.1 0.1 0.9 0.9 4.6 Substandard 4.0 0.4 1.0 0.6 1.3 4.3 — 11.6 Total $ 62.4 $ 38.6 $ 37.3 $ 23.3 $ 13.2 $ 33.3 $ 5.8 $ 213.9 Commercial and floor plans: Pass $ 394.2 $ 165.7 $ 94.5 $ 73.5 $ 47.1 $ 91.3 $ 224.7 $ 1,091.0 Special mention 0.8 11.4 0.8 0.8 3.0 2.3 7.0 26.1 Substandard 1.3 2.8 1.6 2.6 0.6 4.1 2.6 15.6 Total $ 396.3 $ 179.9 $ 96.9 $ 76.9 $ 50.7 $ 97.7 $ 234.3 $ 1,132.7 Commercial purpose secured by 1-4 family: Pass $ 94.9 $ 55.0 $ 27.8 $ 23.1 $ 15.3 $ 32.2 $ 14.4 $ 262.7 Special mention — 0.2 0.2 0.5 0.1 0.6 — 1.6 Substandard 1.3 1.2 0.6 0.6 0.2 1.3 0.1 5.3 Total $ 96.2 $ 56.4 $ 28.6 $ 24.2 $ 15.6 $ 34.1 $ 14.5 $ 269.6 Agricultural: Pass $ 35.1 $ 16.2 $ 9.0 $ 5.4 $ 2.1 $ 1.6 $ 108.9 $ 178.3 Special mention 0.2 4.1 0.1 0.4 0.6 0.3 7.0 12.7 Substandard 4.9 0.7 0.6 2.5 — 0.1 2.6 11.4 Total $ 40.2 $ 21.0 $ 9.7 $ 8.3 $ 2.7 $ 2.0 $ 118.5 $ 202.4 June 30, 2022 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2022 2021 2020 2019 2018 Prior Revolving Loans Amortized Cost Basis Total Residential 1-4 family: Performing $ 83.6 $ 448.6 $ 563.5 $ 106.0 $ 34.0 $ 296.2 $ 0.3 $ 1,532.2 Nonperforming — — 0.1 0.1 0.3 2.3 — 2.8 Total $ 83.6 $ 448.6 $ 563.6 $ 106.1 $ 34.3 $ 298.5 $ 0.3 $ 1,535.0 Consumer home equity and HELOC: Performing $ 9.9 $ 9.7 $ 5.8 $ 3.8 $ 6.3 $ 19.4 $ 468.0 $ 522.9 Nonperforming 0.3 0.4 — 0.1 0.2 1.4 0.1 2.5 Total $ 10.2 $ 10.1 $ 5.8 $ 3.9 $ 6.5 $ 20.8 $ 468.1 $ 525.4 Consumer indirect: Performing $ 164.9 $ 218.8 $ 162.1 $ 79.8 $ 46.2 $ 60.1 $ — $ 731.9 Nonperforming — 0.7 0.4 0.3 0.2 0.4 — 2.0 Total $ 164.9 $ 219.5 $ 162.5 $ 80.1 $ 46.4 $ 60.5 $ — $ 733.9 Consumer direct and advance line: Performing $ 31.7 $ 41.4 $ 24.7 $ 12.6 $ 9.6 $ 11.3 $ 25.9 $ 157.2 Nonperforming — — — — — 0.1 — 0.1 Total $ 31.7 $ 41.4 $ 24.7 $ 12.6 $ 9.6 $ 11.4 $ 25.9 $ 157.3 December 31, 2021 Term Loans Amortized Cost Basis by Origination Year Risk by Collateral 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Residential 1-4 family: Performing $ 360.9 $ 477.0 $ 74.7 $ 27.5 $ 25.7 $ 176.5 $ — $ 1,142.3 Nonperforming — 0.3 — — 0.2 0.8 — 1.3 Total $ 360.9 $ 477.3 $ 74.7 $ 27.5 $ 25.9 $ 177.3 $ — $ 1,143.6 Consumer home equity and HELOC: Performing $ 11.1 $ 7.0 $ 3.7 $ 4.8 $ 3.6 $ 12.0 $ 350.7 $ 392.9 Nonperforming 0.3 — 0.3 — 0.6 0.5 — 1.7 Total $ 11.4 $ 7.0 $ 4.0 $ 4.8 $ 4.2 $ 12.5 $ 350.7 $ 394.6 Consumer indirect: Performing $ 272.6 $ 208.6 $ 108.3 $ 64.0 $ 37.0 $ 45.0 $ — $ 735.5 Nonperforming 0.5 0.5 0.4 0.2 0.1 0.4 — 2.1 Total $ 273.1 $ 209.1 $ 108.7 $ 64.2 $ 37.1 $ 45.4 $ — $ 737.6 Consumer direct and advance line: Performing $ 42.5 $ 27.9 $ 15.0 $ 13.3 $ 5.8 $ 7.6 $ 16.9 $ 129.0 Nonperforming 0.1 — — 0.1 — — — 0.2 Total $ 42.6 $ 27.9 $ 15.0 $ 13.4 $ 5.8 $ 7.6 $ 16.9 $ 129.2 As of June 30, 2022 Consumer Commercial Agricultural Total Credit Card: Performing $ 74.5 $ 114.9 $ 2.0 $ 191.4 Nonperforming 0.3 0.5 — 0.8 Total credit card $ 74.8 $ 115.4 $ 2.0 $ 192.2 As of December 31, 2021 Consumer Commercial Agricultural Total Credit Card: Performing $ 64.4 $ 73.1 $ 1.5 $ 139.0 Nonperforming 0.5 0.1 — 0.6 Total credit card $ 64.9 $ 73.2 $ 1.5 $ 139.6

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	6 Months Ended
	Jun. 30, 2022
Repossessed Assets [Abstract]
Other Real Estate Owned Roll Forward	Other real estate owned is a category of real estate owned by the Company as a result of a default by the borrower. Information with respect to the Company’s other real estate owned is reflected in the following table: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 17.5 $ 2.2 $ 2.0 $ 2.5 Acquired through acquisition — — 15.8 — Additions 0.1 — 0.1 0.3 Dispositions (0.8) (0.2) (1.1) (0.8) Ending balance $ 16.8 $ 2.0 $ 16.8 $ 2.0

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following amounts were recorded on the balance sheet related to cumulative basis adjustment for fair value hedges for the periods indicated: June 30, 2022 December 31, 2021 Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Available-for-sale securities $ 189.5 $ (10.5) $ 695.6 $ (4.4)
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location	The following table summarizes the fair values of our derivative instruments on a gross and net basis for the periods indicated. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements, but after the variation margin payments with central clearing organizations have been applied as settlement, as applicable. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. June 30, 2022 December 31, 2021 Notional Amount Balance Sheet Location Estimated Notional Amount Balance Sheet Location Estimated Derivatives designated as hedges: Interest rate swap contracts $ 200.0 $ 10.3 $ 700.0 $ 4.1 Derivatives not designated as hedges: Interest rate swap contracts 1,758.7 14.3 913.9 22.2 Interest rate lock commitments 28.6 0.2 77.3 1.8 Forward loan sales contracts 34.6 — — — Derivative assets in the balance sheet $ 2,021.9 Other Assets $ 24.8 $ 1,691.2 Other Assets $ 28.1 Derivatives designated as hedges: Interest rate swap contracts $ — $ — $ 87.6 $ 0.1 Derivatives not designated as hedges: Interest rate swap contracts 1,758.7 99.2 913.9 18.1 Risk participation agreements 108.5 0.2 — — Forward loan sales contracts — — 102.4 — Derivative liabilities in the balance sheet $ 1,867.2 Accrued Expenses $ 99.4 $ 1,103.9 Accrued Expenses $ 18.2
Derivatives Not Designated as Hedging Instruments	The table below presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the income statement for the periods indicated: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative Interest rate lock commitments Mortgage banking revenues $ 1.0 $ 0.2 Mortgage banking revenues $ 1.5 $ 0.5
Schedule of Derivative Instruments	The tables below present the gross presentation, the effects of offsetting, and a net presentation of the Company’s derivatives as of the periods indicated: June 30, 2022 Gross Assets Recognized Gross Assets Offset in the Balance Sheet Net Assets in the Balance Sheet Financial Instruments Cash Collateral Received Net Amount Interest rate swap contracts $ 24.6 $ — $ 24.6 $ — $ 23.7 $ 0.9 Mortgage related derivatives 0.2 — 0.2 — — 0.2 Total derivatives 24.8 — 24.8 — 23.7 1.1 Total assets $ 24.8 $ — $ 24.8 $ — $ 23.7 $ 1.1 Gross Liabilities Recognized Gross Liabilities Offset in the Balance Sheet Net Liabilities in the Balance Sheet Financial Instruments Cash Collateral Posted Net Amount Interest rate swap contracts $ 99.2 $ — $ 99.2 $ — $ — $ 99.2 Risk participation agreements 0.2 — 0.2 — — 0.2 Total derivatives 99.4 — 99.4 — — 99.4 Repurchase agreements 1,234.7 — 1,234.7 — 1,234.7 — Total liabilities $ 1,334.1 $ — $ 1,334.1 $ — $ 1,234.7 $ 99.4 December 31, 2021 Gross Assets Recognized Gross Assets Offset in the Balance Sheet Net Assets in the Balance Sheet Financial Instruments Cash Collateral Received Net Amount Interest rate swap contracts $ 26.3 $ — $ 26.3 $ — $ 8.0 $ 18.3 Mortgage related derivatives 1.8 — 1.8 — — 1.8 Total derivatives 28.1 — 28.1 — 8.0 20.1 Total assets $ 28.1 $ — $ 28.1 $ — $ 8.0 $ 20.1 Gross Liabilities Recognized Gross Liabilities Offset in the Balance Sheet Net Liabilities in the Balance Sheet Financial Instruments Cash Collateral Posted Net Amount Interest rate swap contracts $ 18.2 $ — $ 18.2 $ — $ — $ 18.2 Total derivatives 18.2 — 18.2 — — 18.2 Repurchase agreements 1,051.1 — 1,051.1 — 1,051.1 — Total liabilities $ 1,069.3 $ — $ 1,069.3 $ — $ 1,051.1 $ 18.2

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Share	The following table sets forth the computation of basic and diluted earnings per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Net income $ 64.1 $ 42.5 $ 30.7 $ 93.9 Weighted average common shares outstanding for basic earnings per share computation 109,106,891 61,657,593 101,025,926 61,624,917 Dilutive effects of stock-based compensation 24,827 70,228 50,405 98,225 Weighted average common shares outstanding for diluted earnings per common share computation 109,131,718 61,727,821 101,076,331 61,723,142 Basic earnings per common share $ 0.59 $ 0.69 $ 0.30 $ 1.52 Diluted earnings per common share $ 0.59 $ 0.69 $ 0.30 $ 1.52 Anti-dilutive unvested time restricted stock 218,033 84,165 61,058 90,538

Regulatory Capital (Tables)

Regulatory Capital (Tables)	6 Months Ended
	Jun. 30, 2022
Banking and Thrift, Other Disclosures [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	Actual capital amounts and ratios for the Company and its subsidiary Bank, as of June 30, 2022 and December 31, 2021 are presented in the following tables: Actual Minimum Required for Capital Adequacy Purposes For Capital Adequacy Purposes Plus Capital Conservation Buffer Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements(1) June 30, 2022 Amount Ratio Amount Ratio Amount Ratio Amount Ratio Total risk-based capital: Consolidated $ 2,908.7 13.60 % $ 1,710.7 8.00 % $ 2,245.2 10.50 % $ 2,138.3 10.00 % FIB 2,743.7 12.87 1,705.5 8.00 2,238.5 10.50 2,131.9 10.00 Tier 1 risk-based capital: Consolidated 2,451.4 11.46 1,283.0 6.00 1,817.6 8.50 1,710.7 8.00 FIB 2,544.0 11.93 1,279.1 6.00 1,812.1 8.50 1,705.5 8.00 Common equity tier 1 risk-based capital: Consolidated 2,451.4 11.46 962.2 4.50 1,496.8 7.00 1,389.9 6.50 FIB 2,544.0 11.93 959.3 4.50 1,492.3 7.00 1,385.7 6.50 Leverage capital ratio: Consolidated 2,451.4 7.72 1,269.5 4.00 1,269.5 4.00 1,586.8 5.00 FIB 2,544.0 8.03 1,267.0 4.00 1,267.0 4.00 1,583.7 5.00 Actual Minimum Required for Capital Adequacy Purposes For Capital Adequacy Purposes Plus Capital Conservation Buffer Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements(1) December 31, 2021 Amount Ratio Amount Ratio Amount Ratio Amount Ratio Total risk-based capital: Consolidated $ 1,659.3 14.11 % $ 940.9 8.00 % $ 1,235.0 10.50 % $ 1,176.2 10.00 % FIB 1,472.5 12.56 938.0 8.00 1,231.1 10.50 1,172.5 10.00 Tier 1 risk-based capital: Consolidated 1,469.0 12.49 705.7 6.00 999.7 8.50 940.9 8.00 FIB 1,382.2 11.79 703.5 6.00 996.6 8.50 938.0 8.00 Common equity tier 1 risk-based capital: Consolidated 1,384.8 11.77 529.3 4.50 823.3 7.00 764.5 6.50 FIB 1,382.2 11.79 527.6 4.50 820.8 7.00 762.1 6.50 Leverage capital ratio: Consolidated 1,469.0 7.68 765.5 4.00 765.5 4.00 956.9 5.00 FIB 1,382.2 7.24 764.1 4.00 764.1 4.00 955.1 5.00 (1) The ratios to meet the requirements to be deemed “well-capitalized” are only applicable to FIB. However, the Company manages its capital position as if the requirements apply to the consolidated company and has presented the ratios as if they also applied on a consolidated basis.

Comprehensive Text Block List (

Comprehensive Text Block List (Tables)	6 Months Ended
	Jun. 30, 2022
Text Block [Abstract]
financial instruments with off-balance sheet risk	The following table presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Beginning balance $ 6.2 $ 3.4 $ 3.8 $ 3.7 Provision for (reversal of) credit loss expense — — 2.4 (0.3) Ending balance of allowance for off-balance sheet credit losses $ 6.2 $ 3.4 $ 6.2 $ 3.4 June 30, 2022 December 31, 2021 Unused credit card lines $ 811.9 $ 681.6 Commitments to extend credit 4,840.8 2,539.8 Standby letter of credit 91.6 57.5

Other Comprehensive Income_Lo_2

Other Comprehensive Income/Loss (Tables)	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Schedule of Other Comprehensive Income and Related Tax Effects	The gross amounts of each component of other comprehensive loss and the related tax effects are as follows: Pre-tax Tax Expense (Benefit) Net of Tax Three Months Ended June 30, 2022 2021 2022 2021 2022 2021 Investment securities available-for sale: Change in net unrealized loss during period $ (161.6) $ (0.8) $ (45.2) $ (0.2) $ (116.4) $ (0.6) Reclassification adjustment for net loss included in net income 0.1 0.1 — — 0.1 0.1 Net change in unamortized (losses) gains on available-for-sale securities transferred into held-to-maturity (0.9) 24.8 (0.2) 6.3 (0.7) 18.5 Change in net unrealized loss (gain) on derivatives (15.0) (0.8) (4.2) (0.2) (10.8) (0.6) Total other comprehensive (loss) income $ (177.4) $ 23.3 $ (49.6) $ 5.9 $ (127.8) $ 17.4 Pre-tax Tax Expense (Benefit) Net of Tax Six Months Ended June 30, 2022 2021 2022 2021 2022 2021 Investment securities available-for sale: Change in net unrealized loss during period $ (414.2) $ (67.6) $ (107.9) $ (17.2) $ (306.3) $ (50.4) Reclassification adjustment for net loss included in net income 0.2 0.1 — — 0.2 0.1 Reclassification adjustment for securities transferred from held-to-maturity to available-for-sale 0.2 — 0.1 — 0.1 — Net change in unamortized (losses) gains on available-for-sale securities transferred into held-to-maturity (23.9) 24.8 (5.9) 6.3 (18.0) 18.5 Change in net unrealized loss (gain) on derivatives 6.3 (0.9) 1.1 (0.2) 5.2 (0.7) Total other comprehensive loss $ (431.4) $ (43.6) $ (112.6) $ (11.1) $ (318.8) $ (32.5)
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive loss, net of related tax effects, are as follows: June 30, 2022 December 31, 2021 Net unrealized loss on investment securities available-for-sale $ (333.6) $ (29.0) Net unrealized (loss) gain on investment securities transferred to held-to-maturity (3.9) 15.0 Net unrealized gain on derivatives 7.7 3.0 Net accumulated other comprehensive loss $ (329.8) $ (11.0)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis	Financial assets and financial liabilities measured at fair value on a recurring basis are as follows: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Balance Quoted Prices in Significant Other Significant Investment debt securities available-for-sale: U.S. Treasury notes $ 809.8 $ 809.8 $ — $ — State, county, and municipal securities 282.2 — 282.2 — Obligations of U.S. government agencies 225.9 — 225.9 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 4,815.4 — 4,815.4 — Private mortgage-backed securities 253.0 — 253.0 — Collateralized loan obligations 1,094.0 — 1,094.0 — Corporate securities 260.8 — 260.8 — Loans held for sale 127.4 — 127.4 — Derivative assets: Interest rate swap contracts 24.6 — 24.6 — Interest rate lock commitments 0.2 — 0.2 — Derivative liabilities: Interest rate swap contracts 99.2 — 99.2 — Risk participation agreements 0.2 — 0.2 — Deferred compensation plan assets 19.3 — 19.3 — Deferred compensation plan liabilities 19.3 — 19.3 — Fair Value Measurements at Reporting Date Using As of December 31, 2021 Balance Quoted Prices in Significant Other Significant Investment debt securities available-for-sale: U.S. Treasury notes $ 684.7 $ 684.7 $ — $ — State, county and municipal securities 427.5 — 427.5 — Obligations of U.S. government agencies 346.9 — 346.9 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 2,018.1 — 2,018.1 — Private mortgage-backed securities 173.4 — 173.4 — Collateralized loan obligations 899.4 — 899.4 — Corporate securities 270.5 — 270.5 — Loans held for sale 30.1 — 30.1 — Derivative assets: Interest rate swap contracts 26.3 — 26.3 — Interest rate lock commitments 1.8 — 1.8 — Derivative liabilities Interest rate swap contracts 18.2 — 18.2 — Deferred compensation plan assets 21.4 — 21.4 — Deferred compensation plan liabilities 21.4 — 21.4 —
Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Non-Recurring Basis	The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Significant Collateral dependent loans $ 85.5 $ — $ — $ 85.5 Other real estate owned 16.8 — — 16.8 Long-lived assets to be disposed of by sale 7.1 — — 7.1 Fair Value Measurements at Reporting Date Using As of December 31, 2021 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Significant Collateral dependent loans $ 11.7 $ — $ — $ 11.7 Other real estate owned 2.0 — — 2.0 Long-lived assets to be disposed of by sale 1.3 — — 1.3
Fair Value Inputs, Assets, Quantitative Information	The following table presents additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair values: Fair Value As of June 30, 2022 December 31, 2021 Valuation Unobservable Range Collateral dependent loans $ 85.5 $ 11.7 Appraisal Appraisal adjustment 1% - 18% (7%) Other real estate owned 16.8 2.0 Appraisal Appraisal adjustment 0% - 0% 0% Long-lived assets to be disposed of by sale 7.1 1.3 Appraisal Appraisal adjustment 0% - 0% 0%
Fair Value, by Balance Sheet Grouping	The estimated fair values of financial instruments that are reported in the Company’s consolidated balance sheets, and are segregated by the level of the valuation inputs within the fair value hierarchy that are utilized to measure fair value, are as follows: Fair Value Measurements at Reporting Date Using As of June 30, 2022 Carrying Amount Estimated Quoted Prices in Active Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 1,059.3 $ 1,059.3 $ 1,059.3 $ — $ — Securities purchased under agreement to resell 202.2 202.2 — 202.2 — Investment debt securities available-for-sale 7,741.1 7,741.1 809.8 6,931.3 — Investment debt securities held-to-maturity 3,130.0 2,860.5 293.1 2,567.4 — Accrued interest receivable 90.6 90.6 — 90.6 — Mortgage servicing rights, net 32.1 37.0 — 37.0 — Loans held for sale 127.4 127.4 — 127.4 — Net loans held for investment 16,942.1 16,874.0 — 16,788.5 85.5 Derivative assets 24.8 24.8 — 24.8 — Deferred compensation plan assets 19.3 19.3 — 19.3 — Total financial assets $ 29,368.9 $ 29,036.2 $ 2,162.2 $ 26,788.5 $ 85.5 Financial liabilities: Total deposits, excluding time deposits $ 25,368.1 $ 25,368.1 $ 25,368.1 $ — $ — Time deposits 1,495.7 1,467.2 — 1,467.2 — Securities sold under repurchase agreements 1,234.7 1,234.7 — 1,234.7 — Accrued interest payable 4.3 4.3 — 4.3 — Long-term debt 120.4 119.3 — 119.3 — Subordinated debentures held by subsidiary trusts 163.1 157.5 — 157.5 — Derivative liabilities 99.4 99.4 — 99.4 — Deferred compensation plan liabilities 19.3 19.3 — 19.3 — Total financial liabilities $ 28,505.0 $ 28,469.8 $ 25,368.1 $ 3,101.7 $ — Fair Value Measurements at Reporting Date Using As of December 31, 2021 Carrying Amount Estimated Quoted Prices in Active Markets for Significant Other Significant Financial assets: Cash and cash equivalents $ 2,344.8 $ 2,344.8 $ 2,344.8 $ — $ — Investment debt securities available-for-sale 4,820.5 4,820.5 684.7 4,135.8 — Investment debt securities held-to-maturity 1,687.6 1,667.5 — 1,667.5 — Accrued interest receivable 47.4 47.4 — 47.4 — Mortgage servicing rights, net 28.2 28.2 — 28.2 — Loans held for sale 30.1 30.1 — 30.1 — Net loans held for investment 9,209.4 9,254.3 — 9,242.6 11.7 Derivative assets 28.1 28.1 — 28.1 — Deferred compensation plan assets 21.4 21.4 — 21.4 — Total financial assets $ 18,217.5 $ 18,242.3 $ 3,029.5 $ 15,201.1 $ 11.7 Financial liabilities: Total deposits, excluding time deposits $ 15,303.1 $ 15,303.1 $ 15,303.1 $ — $ — Time deposits 966.5 963.1 — 963.1 — Securities sold under repurchase agreements 1,051.1 1,051.1 — 1,051.1 — Accrued interest payable 3.7 3.7 — 3.7 — Long-term debt 112.4 120.7 — 120.7 — Subordinated debentures held by subsidiary trusts 87.0 85.5 — 85.5 — Derivative liabilities 18.2 18.2 — 18.2 — Deferred compensation plan liabilities 21.4 21.4 — 21.4 — Total financial liabilities $ 17,563.4 $ 17,566.8 $ 15,303.1 $ 2,263.7 $ —

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Feb. 01, 2022 USD ($) office $ / shares shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,099.8		$ 1,099.8		$ 621.6	$ 621.6
Estimated useful lives of related deposits				12 years
Acquisition related expenses		45.8	$ 0	$ 111	$ 0
Goodwill, Period Increase (Decrease)		(37.8)
Core Deposits
Business Acquisition [Line Items]
Estimated useful lives of related deposits	10 years			10 years
Great Western Bank
Business Acquisition [Line Items]
Number of banking offices acquired | office	174
Total consideration exchanged	$ 1,723.3
Goodwill	478.2
Core deposit intangibles	50.1
Customer relationship intangible	22.8
Great Western Bank | First Interstate Foundation
Business Acquisition [Line Items]
Acquisition related costs	21.5
Great Western Bank | Scott Family
Business Acquisition [Line Items]
Acquisition related costs	$ 8.2
Great Western Bank | Class A Common Stock
Business Acquisition [Line Items]
Number of shares issued in connection with Cascade merger (in shares) | shares	46,879,601
Price per share of First Interstate Class A common stock (in dollars per share) | $ / shares	$ 36.76
Business acquisition conversion share rate (in shares) | shares	0.8425
Great Western Bank | Customer Relationships
Business Acquisition [Line Items]
Estimated useful lives of related deposits	12 years
Acquisition related costs as defined by ASC 805
Business Acquisition [Line Items]
Acquisition related expenses		$ 1		$ 26.8

Acquisitions - Schedule of Reco

Acquisitions - Schedule of Recognized Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Feb. 01, 2022	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Liabilities assumed:
Goodwill		$ 1,099,800	$ 621,600	$ 621,600
Great Western Bank
Assets acquired:
Cash and cash equivalents	$ 2,006,900
Investment securities	2,699,000
Securities purchased under agreement to resell	101,100
Loans held for sale	217,000
Loans held for investment	7,705,000
Allowance for credit losses	(59,500)
Premises and equipment, including right of use lease assets	144,900
Other real estate owned (“OREO”)	15,800
Company owned life insurance	186,600
Core deposit intangibles	50,100
Customer relationship intangible	22,800
Mortgage servicing rights	1,300
Deferred tax assets, net	63,600
Other assets	198,000
Total assets acquired	13,352,600
Liabilities assumed:
Deposits	11,688,000
Securities sold under repurchase agreements	74,000
Accrued expenses and other liabilities	110,100
FHLB advances	122,900
Subordinated debt	36,400
Subordinated debentures held by subsidiary trusts	76,100
Total liabilities assumed	12,107,500
Net assets acquired	1,245,100
Class A common stock	1,723,300
Total consideration paid (1)	1,723,300
Goodwill	478,200
Cash paid in lieu of fractional shares	$ 13

Acquisitions - Schedule of Acqu

Acquisitions - Schedule of Acquired loans with Credit Impairment (Details) $ in Millions	Feb. 01, 2022 USD ($)
Business Acquisition [Line Items]
Purchase price (initial fair value)	$ 623.3
Allowance for credit losses	298.2
Great Western Bank
Business Acquisition [Line Items]
Unpaid principal balance	979.2
Credit discount	69.2
Discount attributable to other factors	29.9
Purchase price (initial fair value)	623.3
Allowance for credit losses	59.5
Amortized cost basis	$ 682.8

Acquisitions - Schedule of Ac_2

Acquisitions - Schedule of Acquired Loans not Deemed to Have Credit Impairment (Details) $ in Millions	Feb. 01, 2022 USD ($)
Business Acquisition [Line Items]
Purchase price (initial fair value)	$ 623.3
Allowance for credit losses	298.2
Great Western Bank
Business Acquisition [Line Items]
Unpaid principal balance	979.2
Principal amounts previously written off by GWB	(238.7)
Interest applied to principal by GWB	(18.1)
Adjusted unpaid principal balance	722.4
Credit discount	(69.2)
Discount attributable to other factors	(29.9)
Purchase price (initial fair value)	623.3
Allowance for credit losses	59.5
Amortized cost basis	682.8
Unpaid principal balance	7,107.9
Credit discount (1)	(76.5)
Non-credit discount	(9.2)
Fair value	7,022.2
Amortized cost basis	$ 7,705

Acquisitions - Summary of Pro F

Acquisitions - Summary of Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 0.93	$ 1.33	$ 1.76	$ 0.61
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 0.93	$ 1.33	$ 1.76	$ 0.61
Great Western Bank
Business Acquisition [Line Items]
Total revenues	$ 300.7	$ 291.8	$ 569.6	$ 613.4
Net income	$ 101.1	$ 144.6	$ 177.5	$ 66.4

Schedule of Adjustments to Good

Schedule of Adjustments to Goodwill (Details) $ in Millions	3 Months Ended
	Jun. 30, 2022 USD ($)
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	$ (37.8)
Accrued expenses and other liabilties
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	3
Total liability adjustments
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	3
Loans held for sale
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	35.1
Loans held for investment
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	(8.4)
Allowance for credit losses
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	24.8
Premises and equipment
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	0.8
Core deposit intangibles
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	1
Deferred tax assets
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	(12.5)
Total asset adjustments
Business Acquisition [Line Items]
Goodwill, Period Increase (Decrease)	$ 40.8

Goodwill and Core Deposit Int_3

Goodwill and Core Deposit Intangibles - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended
	Feb. 01, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill				$ 0
Goodwill [Line Items]
Amortization of intangible assets		$ 4,100,000	$ 2,500,000	$ 7,700,000	$ 5,000,000
Weighted average useful lives of related deposits				12 years
Core Deposits
Goodwill [Line Items]
Weighted average useful lives of related deposits	10 years			10 years

Goodwill and Core Deposit Int_4

Goodwill and Core Deposit Intangibles - Goodwill Carrying Value (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Net carrying value at beginning of the period	$ 621.6	$ 621.6
Provisional additions to goodwill from acquisition	478.2	0
Net carrying value at end of period	$ 1,099.8	$ 621.6

Goodwill and Core Deposit Int_5

Goodwill and Core Deposit Intangibles - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
2023	$ 15.6
Finite-lived Intangible Assets [Roll Forward]
Gross other intangible assets, at beginning of the period		$ 106	$ 106
Provisional amounts established through acquisition	72.9
Finite-Lived Intangible Assets, Period Increase (Decrease)	(1.4)
Accumulated amortization	(72.4)	(64.7)
Net other intangible assets, end of period	105.1	41.3
Core Deposits
Finite-Lived Intangible Assets [Line Items]
2023	13.7
Finite-lived Intangible Assets [Roll Forward]
Gross other intangible assets, at beginning of the period		106	106
Provisional amounts established through acquisition	50.1
Finite-Lived Intangible Assets, Period Increase (Decrease)	(1.4)
Accumulated amortization	(71.6)	(64.7)
Net other intangible assets, end of period	83.1	41.3
OCRI
Finite-Lived Intangible Assets [Line Items]
2023	1.9
Finite-lived Intangible Assets [Roll Forward]
Gross other intangible assets, at beginning of the period		0	$ 0
Provisional amounts established through acquisition	22.8
Finite-Lived Intangible Assets, Period Increase (Decrease)	0
Accumulated amortization	(0.8)	0
Net other intangible assets, end of period	$ 22	$ 0

Goodwill and Core Deposit Int_6

Goodwill and Core Deposit Intangibles - Schedule of Future Amortization Expense (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
2022 remaining	$ 8.1
2023	15.6
2024	14.6
2025	13.7
2026	12.8
Finite-Lived Intangible Asset, Expected Amortization, After Year Four	40.3
Total	105.1	$ 41.3
Core Deposits
Finite-Lived Intangible Assets [Line Items]
2022 remaining	7.2
2023	13.7
2024	12.7
2025	11.8
2026	10.9
Finite-Lived Intangible Asset, Expected Amortization, After Year Four	26.8
Total	83.1	41.3
OCRI
Finite-Lived Intangible Assets [Line Items]
2022 remaining	0.9
2023	1.9
2024	1.9
2025	1.9
2026	1.9
Finite-Lived Intangible Asset, Expected Amortization, After Year Four	13.5
Total	$ 22	$ 0

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Approximate Fair Values of Investment Securities (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Available-for-Sale:
Amortized Cost	$ 8,193,800,000	$ 4,859,300,000
Gross Unrealized Gains	3,500,000	20,600,000
Gross Unrealized Losses	(456,200,000)	(59,400,000)
Estimated Fair Value	7,741,100,000	4,820,500,000
Held-to-Maturity:
Amortized Cost	3,131,600,000	1,687,600,000
Allowance for Credit Losses	(1,600,000)	0	$ (1,600,000)	$ 0	$ 0	$ 0
Net Carrying Amount	3,130,000,000	1,687,600,000
Gross Unrealized Gains	500,000	15,600,000
Gross Unrealized Losses	(270,000,000)	(35,700,000)
Estimated Fair Value	2,860,500,000	1,667,500,000
U.S. Treasury notes
Available-for-Sale:
Amortized Cost	871,000,000	697,600,000
Gross Unrealized Gains	1,400,000	0
Gross Unrealized Losses	(62,600,000)	(12,900,000)
Estimated Fair Value	809,800,000	684,700,000
Held-to-Maturity:
Amortized Cost	296,700,000
Allowance for Credit Losses	0
Net Carrying Amount	296,700,000
Gross Unrealized Gains	0
Gross Unrealized Losses	(3,600,000)
Estimated Fair Value	293,100,000
State, county, and municipal securities
Available-for-Sale:
Amortized Cost	325,000,000	434,700,000
Gross Unrealized Gains	100,000	2,100,000
Gross Unrealized Losses	(42,900,000)	(9,300,000)
Estimated Fair Value	282,200,000	427,500,000
Held-to-Maturity:
Amortized Cost	186,600,000	67,600,000
Allowance for Credit Losses	(100,000)	0
Net Carrying Amount	186,500,000	67,600,000
Gross Unrealized Gains	500,000	2,000,000
Gross Unrealized Losses	(24,000,000)	(400,000)
Estimated Fair Value	163,000,000	69,200,000
Obligations of U.S. government agencies
Available-for-Sale:
Amortized Cost	235,300,000	356,000,000
Gross Unrealized Gains	0	100,000
Gross Unrealized Losses	(9,400,000)	(9,200,000)
Estimated Fair Value	225,900,000	346,900,000
Held-to-Maturity:
Amortized Cost	328,100,000
Allowance for Credit Losses	0
Net Carrying Amount	328,100,000
Gross Unrealized Gains	0
Gross Unrealized Losses	(28,900,000)
Estimated Fair Value	299,200,000
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations
Available-for-Sale:
Amortized Cost	5,054,700,000	2,027,300,000
Gross Unrealized Gains	2,000,000	14,100,000
Gross Unrealized Losses	(241,300,000)	(23,300,000)
Estimated Fair Value	4,815,400,000	2,018,100,000
Held-to-Maturity:
Amortized Cost	2,236,000,000	1,609,000,000
Allowance for Credit Losses	0	0
Net Carrying Amount	2,236,000,000	1,609,000,000
Gross Unrealized Gains	0	13,200,000
Gross Unrealized Losses	(208,700,000)	(35,300,000)
Estimated Fair Value	2,027,300,000	1,586,900,000
Debt Securities, Held-To-Maturity, Transfer, Unamortized Gain	15,900,000	20,100,000
Debt Securities, Held-To-Maturity, Transfer, Unamortized Loss	(21,100,000)
Private mortgage-backed securities
Available-for-Sale:
Amortized Cost	278,100,000	174,400,000
Gross Unrealized Gains	0	100,000
Gross Unrealized Losses	(25,100,000)	(1,100,000)
Estimated Fair Value	253,000,000	173,400,000
Collateralized Loan Obligations
Available-for-Sale:
Amortized Cost	1,145,700,000	898,200,000
Gross Unrealized Gains	0	1,200,000
Gross Unrealized Losses	(51,700,000)	0
Estimated Fair Value	1,094,000,000	899,400,000
Corporate Debt Securities
Available-for-Sale:
Amortized Cost	284,000,000	271,100,000
Gross Unrealized Gains	0	3,000,000
Gross Unrealized Losses	(23,200,000)	(3,600,000)
Estimated Fair Value	260,800,000	270,500,000
Held-to-Maturity:
Amortized Cost	84,200,000	11,000,000
Allowance for Credit Losses	(1,500,000)	0
Net Carrying Amount	82,700,000	11,000,000
Gross Unrealized Gains	0	400,000
Gross Unrealized Losses	(4,800,000)	0
Estimated Fair Value	$ 77,900,000	$ 11,400,000

Investment Securities - Gross U

Investment Securities - Gross Unrealized Losses and Fair Values of Investment Securities (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Available-for-Sale:
Fair Value, Less than 12 Months	$ 5,830.5	$ 2,760.3
Gross Unrealized Losses, Less than 12 Months	(287.1)	(58.3)
Fair Value, 12 Months or Longer	1,331.9	68.7
Gross Unrealized Losses, 12 Months or Longer	(169.1)	(1.1)
Fair Value, Total	7,162.4	2,829
Gross Unrealized Losses, Total	(456.2)	(59.4)
US Treasury Notes Securities
Available-for-Sale:
Fair Value, Less than 12 Months	177.6
Gross Unrealized Losses, Less than 12 Months	(23)
Fair Value, 12 Months or Longer	458.1
Gross Unrealized Losses, 12 Months or Longer	(39.6)
Fair Value, Total	635.7
Gross Unrealized Losses, Total	(62.6)
U.S. Treasury notes
Available-for-Sale:
Fair Value, Less than 12 Months		684.7
Gross Unrealized Losses, Less than 12 Months		(12.9)
Fair Value, 12 Months or Longer		0
Gross Unrealized Losses, 12 Months or Longer		0
Fair Value, Total		684.7
Gross Unrealized Losses, Total		(12.9)
State, county, and municipal securities
Available-for-Sale:
Fair Value, Less than 12 Months	136.7	278.7
Gross Unrealized Losses, Less than 12 Months	(15.8)	(9.1)
Fair Value, 12 Months or Longer	123.3	5
Gross Unrealized Losses, 12 Months or Longer	(27.1)	(0.2)
Fair Value, Total	260	283.7
Gross Unrealized Losses, Total	(42.9)	(9.3)
Obligations of U.S. government agencies
Available-for-Sale:
Fair Value, Less than 12 Months	191.7	297
Gross Unrealized Losses, Less than 12 Months	(6.5)	(8.9)
Fair Value, 12 Months or Longer	28.1	16.4
Gross Unrealized Losses, 12 Months or Longer	(2.9)	(0.3)
Fair Value, Total	219.8	313.4
Gross Unrealized Losses, Total	(9.4)	(9.2)
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations
Available-for-Sale:
Fair Value, Less than 12 Months	3,838.2	1,262.8
Gross Unrealized Losses, Less than 12 Months	(159.7)	(23)
Fair Value, 12 Months or Longer	621.8	26.4
Gross Unrealized Losses, 12 Months or Longer	(81.6)	(0.3)
Fair Value, Total	4,460	1,289.2
Gross Unrealized Losses, Total	(241.3)	(23.3)
Private mortgage-backed securities
Available-for-Sale:
Fair Value, Less than 12 Months	242.9	127.2
Gross Unrealized Losses, Less than 12 Months	(24.2)	(1.1)
Fair Value, 12 Months or Longer	10.1	0
Gross Unrealized Losses, 12 Months or Longer	(0.9)	0
Fair Value, Total	253	127.2
Gross Unrealized Losses, Total	(25.1)	(1.1)
Collateralized Loan Obligations
Available-for-Sale:
Fair Value, Less than 12 Months	1,094
Gross Unrealized Losses, Less than 12 Months	(51.7)
Fair Value, 12 Months or Longer	0
Gross Unrealized Losses, 12 Months or Longer	0
Fair Value, Total	1,094
Gross Unrealized Losses, Total	(51.7)
Corporate Debt Securities
Available-for-Sale:
Fair Value, Less than 12 Months	149.4	109.9
Gross Unrealized Losses, Less than 12 Months	(6.2)	(3.3)
Fair Value, 12 Months or Longer	90.5	20.9
Gross Unrealized Losses, 12 Months or Longer	(17)	(0.3)
Fair Value, Total	239.9	130.8
Gross Unrealized Losses, Total	$ (23.2)	$ (3.6)

Investment Securities - Narrati

Investment Securities - Narrative (Details)		6 Months Ended
	Feb. 01, 2022 USD ($)	Jun. 30, 2022 USD ($) Investments	Jun. 30, 2021 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Investments	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Transfer, Amount	$ 10,700,000
Debt Securities, Held-To-Maturity, After Allowance For Credit Loss, Transfer, Amount	10,900,000
Debt Securities, Available-For-Sale, Amortized Cost, after Allowance for Credit Loss, Transfer, Amount	485,900,000
Debt Securities, Available-For-Sale, after Allowance for Credit Loss, Transfer, Amount	463,600,000
Debt Securities, Held-to-maturity, Transfer to Trading, Unrealized Gain (Loss)	0
Allowance for Credit Losses		$ 0			$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss		1,600,000	$ 0	$ 1,600,000	0	$ 0	$ 0
Interest Receivable		90,600,000			47,400,000
Debt Securities, Available-for-sale, Realized Gain		0	0
Debt Securities, Available-for-sale, Realized Loss		0	$ 0
Debt Securities, Available-for-sale, Amortized Cost		8,193,800,000			4,859,300,000
Securities Sold under Agreements to Repurchase, Fair Value of Collateral		4,871,300,000			2,617,800,000
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		$ 4,526,500,000			$ 2,610,800,000
Investment securities in an unrealized loss position (securities) | Investments		1,155			285
Great Western Bank
Schedule of Held-to-maturity Securities [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Debt Securities, Available-For-Sale	2,356,900,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Debt Securities, Held-To-Maturity	$ 342,100,000
Debt Securities
Schedule of Held-to-maturity Securities [Line Items]
Interest Receivable		$ 30,800,000			$ 16,600,000
Callable Within One Year
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost of investment securities callable after one year but within five years		813,900,000
Fair value of investment securities callable after one year but within five years		775,900,000
Callable structured notes amortized costs		$ 0

Investment Securities - Held-To

Investment Securities - Held-To-Maturity Allowance For Credit Loss (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,600,000	$ 0	$ 0	$ 0
Provision for credit loss expense	0	0	1,600,000	0
Ending balance of allowance for credit losses	$ 1,600,000	$ 0	$ 1,600,000	$ 0

Investment Securities - Credit

Investment Securities - Credit Quality Indicators (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	$ 3,131.6	$ 1,687.6
AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	2,930.2	1,626.2
AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	95.1	31.6
A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	16	18.7
BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	75.2	7
Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	15.1	4.1
U.S. Treasury notes
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	296.7
U.S. Treasury notes | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	296.7
U.S. Treasury notes | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
U.S. Treasury notes | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
U.S. Treasury notes | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
U.S. Treasury notes | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
State, county, and municipal securities
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	186.6	67.6
State, county, and municipal securities | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	69.4	17.2
State, county, and municipal securities | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	95.1	31.6
State, county, and municipal securities | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	12	14.7
State, county, and municipal securities | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
State, county, and municipal securities | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	10.1	4.1
Obligations of U.S. government agencies
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	328.1
Obligations of U.S. government agencies | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	328.1
Obligations of U.S. government agencies | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
Obligations of U.S. government agencies | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
Obligations of U.S. government agencies | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
Obligations of U.S. government agencies | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0
Corporate securities
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	84.2	11
Corporate securities | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
Corporate securities | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
Corporate securities | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	4	4
Corporate securities | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	75.2	7
Corporate securities | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	5	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	2,236	1,609
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	1,903.2	1,439.1
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	1,903.2	1,439.1
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | FNMA/FHLMC | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	332.8	169.9
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA | AAA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	332.8	169.9
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA | AA
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA | A
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA | BBB
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	0	0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | GNMA | Not Rated
Schedule of Held-to-maturity Securities [Line Items]
Investment securities classified as held to maturity	$ 0	$ 0

Investment Securities - Maturit

Investment Securities - Maturities of Investment Securities (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Available-for-Sale, Amortized Cost
Available-for-Sale Amortized Cost, Within One Year	$ 84.8
Available-for-Sale Amortized Cost, After One Year but Within Five Years	1,566.4
Available-for-Sale Amortized Cost, After Five Years but Within Ten Years	1,865.4
Available-for-Sale Amortized Cost, After Ten Years	4,677.2
Amortized Cost	8,193.8	$ 4,859.3
Available-for-Sale, Estimated Fair Value
Available-for-Sale Estimated Fair Value, Within One Year	84.4
Available-for-Sale Estimated Fair Value, After One Year but Within Five Years	1,507.7
Available-for-Sale Estimated Fair Value, After Five Years but Within Ten Years	1,738.6
Available-for-Sale Estimated Fair Value, After Ten Years	4,410.4
Available-for-Sale, Estimated Fair Value	7,741.1	4,820.5
Held-to-Maturity, Amortized Cost
Held-to-Maturity Amortized Cost, Within One Year	10.1
Held-to-Maturity Amortized Cost, After One Year but Within Five Years	375
Held-to-Maturity Amortized Cost, After Five Years but Within Ten Years	784.5
Held-to-Maturity Amortized Cost, After Ten Years	1,962
Amortized Cost	3,131.6	1,687.6
Held-to-Maturity, Estimated Fair Value
Held-to-Maturity Estimated Fair Value, Within One Year	10.1
Held-to-Maturity Estimated Fair Value, After One Year but Within Five Years	367.9
Held-to-Maturity Estimated Fair Value, After Five Years but Within Ten Years	718.4
Held-to-Maturity Estimated Fair Value, After Ten Years	1,764.1
Held-to-Maturity, Estimated Fair Value	2,860.5	1,667.5
Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase, Fair Value of Collateral	4,871.3	2,617.8
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	$ 4,526.5	$ 2,610.8

Loans Held for Sale - Narrative

Loans Held for Sale - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Mortgage loans held for sale	$ 127.4		$ 127.4		$ 30.1
Transfer of loans from held-for-sale to held for investment			19.8	$ 0
Proceeds from Collection of Loans Held-for-sale	53.9	$ 4.5
Goodwill, Period Increase (Decrease)	(37.8)
Loans held for sale
Debt Securities, Available-for-sale [Line Items]
Goodwill, Period Increase (Decrease)	35.1
Commercial
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	13.9		$ 13.9		$ 5
Proceeds from Sale of Loans Held-for-sale	$ 23.4

Loans Held for Investment - Sch

Loans Held for Investment - Schedule of Loans by Segment (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Deferred loan fees and costs	$ (10.6)		$ (12.3)
Loans held for investment, net of deferred fees and costs	17,162.5		9,331.7
Allowance for credit losses	(220.4)	$ (247.2)	(122.3)	$ (135.5)	$ (136.6)	$ (144.3)
Net loans held for investment	16,942.1		9,209.4
Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	7,857.7		3,971.5
Allowance for credit losses	(89.5)	(125)	(43.9)	(51.1)	(52.2)	(54.8)
Financing Receivable, Loan in Process	7.9		2.7
Commercial real estate | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	5.1		1.1
Commercial real estate | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2.1		1
Commercial real estate | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.7		0.6
Commercial real estate | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	7,820.1		3,960.8
Land acquisition & development
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	355.7		247.8
Allowance for credit losses	(0.8)	(0.5)	(0.5)	(1)	(1.2)	(1.3)
Financing Receivable, Loan in Process	0.8		0.2
Land acquisition & development | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.7		0.2
Land acquisition & development | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.1		0
Land acquisition & development | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Land acquisition & development | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	350.8		246.9
Residential
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	444.8		262
Allowance for credit losses	(3.4)	(3.3)	(2.4)	(1.5)	(1.4)	(1.6)
Financing Receivable, Loan in Process	1.4		4.2
Residential | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1		4.2
Residential | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.4		0
Residential | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Residential | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	443.4		257.8
Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	959		498
Allowance for credit losses	(14.9)	(10.2)	(6)	(8)	(7.2)	(7.3)
Financing Receivable, Loan in Process	10.7		0
Commercial | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	10.7		0
Commercial | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Commercial | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Commercial | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	948.3		498
Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	1,759.5		1,007.8
Financing Receivable, Loan in Process	12.9		4.4
Total construction loans | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	12.4		4.4
Total construction loans | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.5		0
Total construction loans | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Total construction loans | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1,742.5		1,002.7
Residential
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	2,060.4		1,538.2
Allowance for credit losses	(19.7)	(20.1)	(14.6)	(14.8)	(12.9)	(12.8)
Financing Receivable, Loan in Process	5.7		3.9
Residential | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	3.2		3
Residential | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2.1		0.8
Residential | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.4		0.1
Residential | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2,049.7		1,531.4
Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	821.5		213.9
Allowance for credit losses	(5.4)	(10.5)	(1.9)	(3)	(2.8)	(2.7)
Financing Receivable, Loan in Process	2.4		2.1
Agricultural | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2.1		1.9
Agricultural | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0.2
Agricultural | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.3		0
Agricultural | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	781.2		206.9
Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	12,499.1		6,731.4
Allowance for credit losses	(133.7)	(169.6)	(69.3)	(79.4)	(77.7)	(80.5)
Financing Receivable, Loan in Process	28.9		13.1
Total real estate loans | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	22.8		10.4
Total real estate loans | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	4.7		2
Total real estate loans | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1.4		0.7
Total real estate loans | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	12,393.5		6,701.8
Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	733.9		737.6
Allowance for credit losses	(13.1)	(13.5)	(14.3)	(15.8)	(16)	(16.7)
Financing Receivable, Loan in Process	6.9		6.9
Indirect consumer | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	5.3		5.1
Indirect consumer | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1.4		1.4
Indirect consumer | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.2		0.4
Indirect consumer | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	725.2		729
Direct and advance lines
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	157.3		129.2
Allowance for credit losses	(5)	(4.6)	(4.6)	(4.6)	(4.8)	(4.6)
Financing Receivable, Loan in Process	0.8		0.8
Direct and advance lines | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.6		0.5
Direct and advance lines | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.2		0.2
Direct and advance lines | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0.1
Direct and advance lines | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	156.3		128.3
Credit card
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	74.8		64.9
Allowance for credit losses	(2.2)	(2.3)	(2.2)	(1.6)	(1.5)	(2.6)
Financing Receivable, Loan in Process	1.1		1.3
Credit card | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.6		0.6
Credit card | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.2		0.2
Credit card | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.3		0.5
Credit card | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	73.7		63.6
Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	966		931.7
Allowance for credit losses	(20.3)	(20.4)	(21.1)	(22)	(22.3)	(23.9)
Financing Receivable, Loan in Process	8.8		9
Total consumer loans | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	6.5		6.2
Total consumer loans | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1.8		1.8
Total consumer loans | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.5		1
Total consumer loans | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	955.2		920.9
Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	3,036		1,475.5
Allowance for credit losses	(59.9)	(58.2)	(31.6)	(33.7)	(36)	(39.2)
Financing Receivable, Loan in Process	11.5		6.7
Commercial | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	8.4		4.9
Commercial | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2.1		0.7
Commercial | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	1		1.1
Commercial | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	3,010.6		1,463.8
Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	672		203.9
Allowance for credit losses	(6.5)	$ 1	(0.3)	$ (0.4)	$ (0.6)	$ (0.7)
Financing Receivable, Loan in Process	10.1		0.7
Agricultural | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	10		0.7
Agricultural | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0.1		0
Agricultural | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	0		0
Agricultural | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	647.5		201.6
Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	0		1.5
Financing Receivable, Loan in Process			0
Other, including overdrafts | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process			0
Other, including overdrafts | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process			0
Other, including overdrafts | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process			0
Other, including overdrafts | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process			1.5
Loans And Leases Held For Investment [Member]
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Loans held for investment	17,173.1		9,344
Financing Receivable, Loan in Process	59.3		29.5
Loans And Leases Held For Investment [Member] | 30 to 59 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	47.7		22.2
Loans And Leases Held For Investment [Member] | 60 to 89 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	8.7		4.5
Loans And Leases Held For Investment [Member] | Equal to or Greater than 90 Days Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	2.9		2.8
Loans And Leases Held For Investment [Member] | Financial Asset, Not Past Due
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Financing Receivable, Loan in Process	$ 17,006.8		$ 9,289.6

Loans Held for Investment - S_2

Loans Held for Investment - Schedule of Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 247.2	$ 136.6	$ 122.3	$ 144.3
Provisional ACL Recorded for PCD loans	(24.8)		59.5
Provision for (reversal of) credit losses	(1.7)	0	59.6	(5.1)
Loans Charged-Off	(3.7)	(4.8)	(23.6)	(9.7)
Recoveries Collected	3.4	3.7	6.6	5.7
Ending balance	220.4	135.5	220.4	135.5
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	(1.7)	0	55.6	(4.8)
Great Western Bank
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	68.3
Non-owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	45.2	23	17.3	25.5
Provisional ACL Recorded for PCD loans	(6.9)		17.2
Provision for (reversal of) credit losses	(8.8)	(0.2)	(2.1)	(2.7)
Loans Charged-Off	0	0	(2.9)	0
Recoveries Collected	0	0.1	0	0.1
Ending balance	29.5	22.9	29.5	22.9
Owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	25.2	17.4	13.3	18.3
Provisional ACL Recorded for PCD loans	0		9.5
Provision for (reversal of) credit losses	1.4	1.4	6	0.6
Loans Charged-Off	0	(2.2)	(2.2)	(2.3)
Recoveries Collected	0	0	0	0
Ending balance	26.6	16.6	26.6	16.6
Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	54.6	11.8	13.3	11
Provisional ACL Recorded for PCD loans	(19)		10.9
Provision for (reversal of) credit losses	(2.9)	(0.2)	8.5	0.6
Loans Charged-Off	0	0	0	0
Recoveries Collected	0.7	0	0.7	0
Ending balance	33.4	11.6	33.4	11.6
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	125	52.2	43.9	54.8
Provisional ACL Recorded for PCD loans	(25.9)		37.6
Provision for (reversal of) credit losses	(10.3)	1	12.4	(1.5)
Loans Charged-Off	0	(2.2)	(5.1)	(2.3)
Recoveries Collected	0.7	0.1	0.7	0.1
Ending balance	89.5	51.1	89.5	51.1
Agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(1)	0.6	0.3	0.7
Provisional ACL Recorded for PCD loans	1.1		4.5
Provision for (reversal of) credit losses	6.3	0	5.8	(0.1)
Loans Charged-Off	(0.1)	(0.2)	(5.4)	(0.2)
Recoveries Collected	0.2	0	1.3	0
Ending balance	6.5	0.4	6.5	0.4
Commercial and floor plans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	52.9	31	27.1	34.2
Provisional ACL Recorded for PCD loans	0		11.2
Provision for (reversal of) credit losses	1.9	(3.4)	20.3	(5.2)
Loans Charged-Off	(1.1)	(0.3)	(5.3)	(2.1)
Recoveries Collected	0.4	1.7	0.8	2.1
Ending balance	54.1	29	54.1	29
Commercial purpose secured by 1-4 family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	5	4.7	4.4	4.7
Provisional ACL Recorded for PCD loans	0		0.2
Provision for (reversal of) credit losses	0.4	(0.4)	0.8	(0.6)
Loans Charged-Off	0	(0.1)	0	(0.1)
Recoveries Collected	0.1	0.2	0.1	0.4
Ending balance	5.5	4.4	5.5	4.4
Land acquisition & development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0.5	1.2	0.5	1.3
Provisional ACL Recorded for PCD loans	0		3.4
Provision for (reversal of) credit losses	0.2	(0.4)	(0.6)	(0.6)
Loans Charged-Off	0	(0.1)	(2.7)	(0.1)
Recoveries Collected	0.1	0.3	0.2	0.4
Ending balance	0.8	1	0.8	1
Residential construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3.3	1.4	2.4	1.6
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	0.1	0.2	1	0
Loans Charged-Off	0	(0.1)	0	(0.1)
Recoveries Collected	0	0	0	0
Ending balance	3.4	1.5	3.4	1.5
Commercial construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10.2	7.2	6	7.3
Provisional ACL Recorded for PCD loans	0		0.2
Provision for (reversal of) credit losses	4.7	0.9	8.7	0.7
Loans Charged-Off	0	(0.1)	0	(0.1)
Recoveries Collected	0	0	0	0.1
Ending balance	14.9	8	14.9	8
Total construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	9.8	8.9	10.2
Provisional ACL Recorded for PCD loans	0		3.6
Provision for (reversal of) credit losses	5	0.7	9.1	0.1
Loans Charged-Off	0	(0.3)	(2.7)	(0.3)
Recoveries Collected	0.1	0.3	0.2	0.5
Ending balance	19.1	10.5	19.1	10.5
Residential 1-4 family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18.7	11.5	13.4	11.4
Provisional ACL Recorded for PCD loans	0		0.1
Provision for (reversal of) credit losses	(0.7)	1.9	4.5	2
Loans Charged-Off	0	0	(0.1)	0
Recoveries Collected	0.2	0	0.3	0
Ending balance	18.2	13.4	18.2	13.4
Home equity and HELOC
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1.4	1.4	1.2	1.4
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	(0.1)	(0.1)	0	(0.1)
Loans Charged-Off	0	0	0	(0.1)
Recoveries Collected	0.2	0.1	0.3	0.2
Ending balance	1.5	1.4	1.5	1.4
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	20.1	12.9	14.6	12.8
Provisional ACL Recorded for PCD loans	0		0.1
Provision for (reversal of) credit losses	(0.8)	1.8	4.5	1.9
Loans Charged-Off	0	0	(0.1)	(0.1)
Recoveries Collected	0.4	0.1	0.6	0.2
Ending balance	19.7	14.8	19.7	14.8
Agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10.5	2.8	1.9	2.7
Provisional ACL Recorded for PCD loans	0		2.3
Provision for (reversal of) credit losses	(5.1)	0.2	1.3	0.3
Loans Charged-Off	(0.1)	0	(0.2)	0
Recoveries Collected	0.1	0	0.1	0
Ending balance	5.4	3	5.4	3
Total real estate loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	169.6	77.7	69.3	80.5
Provisional ACL Recorded for PCD loans	(25.9)		43.6
Provision for (reversal of) credit losses	(11.2)	3.7	27.3	0.8
Loans Charged-Off	(0.1)	(2.5)	(8.1)	(2.7)
Recoveries Collected	1.3	0.5	1.6	0.8
Ending balance	133.7	79.4	133.7	79.4
Indirect consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	13.5	16	14.3	16.7
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	(0.4)	(0.2)	(0.7)	(0.2)
Loans Charged-Off	(0.8)	(0.8)	(1.7)	(2.1)
Recoveries Collected	0.8	0.8	1.2	1.4
Ending balance	13.1	15.8	13.1	15.8
Direct and advance lines
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4.6	4.8	4.6	4.6
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	0.5	0	0.4	0.7
Loans Charged-Off	(0.6)	(0.4)	(1.4)	(1.2)
Recoveries Collected	0.5	0.2	1.4	0.5
Ending balance	5	4.6	5	4.6
Credit card
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	2.3	1.5	2.2	2.6
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	0.7	0.3	1.3	(0.4)
Loans Charged-Off	(0.9)	(0.4)	(1.5)	(1)
Recoveries Collected	0.1	0.2	0.2	0.4
Ending balance	2.2	1.6	2.2	1.6
Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	20.4	22.3	21.1	23.9
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	0.8	0.1	1	0.1
Loans Charged-Off	(2.3)	(1.6)	(4.6)	(4.3)
Recoveries Collected	1.4	1.2	2.8	2.3
Ending balance	20.3	22	20.3	22
Credit card
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0.3	0.3	0.1	0.3
Provisional ACL Recorded for PCD loans	0		0
Provision for (reversal of) credit losses	0.1	0	0.4	0.2
Loans Charged-Off	(0.1)	(0.1)	(0.2)	(0.3)
Recoveries Collected	0	0.1	0	0.1
Ending balance	0.3	0.3	0.3	0.3
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	58.2	36	31.6	39.2
Provisional ACL Recorded for PCD loans	0		11.4
Provision for (reversal of) credit losses	2.4	(3.8)	21.5	(5.6)
Loans Charged-Off	(1.2)	(0.5)	(5.5)	(2.5)
Recoveries Collected	0.5	2	0.9	2.6
Ending balance	$ 59.9	$ 33.7	$ 59.9	$ 33.7

Loans Held for Investment - S_3

Loans Held for Investment - Schedule of Allowance for Credit Losses for Loans Held for Investment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 247.2	$ 136.6	$ 122.3	$ 144.3
Provision charged to operating expense	(1.7)	0	59.6	(5.1)
Loans Charged-Off	(3.7)	(4.8)	(23.6)	(9.7)
Ending balance	220.4	135.5	220.4	135.5
Financing Receivable, Allowance for Credit Loss, Recovery	3.4	3.7	6.6	5.7
Commercial Real Estate Non Owner Occupied Loans [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	45.2	23	17.3	25.5
Provision charged to operating expense	(8.8)	(0.2)	(2.1)	(2.7)
Loans Charged-Off	0	0	(2.9)	0
Ending balance	29.5	22.9	29.5	22.9
Financing Receivable, Allowance for Credit Loss, Recovery	0	0.1	0	0.1
Agricultural Financing Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(1)	0.6	0.3	0.7
Provision charged to operating expense	6.3	0	5.8	(0.1)
Loans Charged-Off	(0.1)	(0.2)	(5.4)	(0.2)
Ending balance	6.5	0.4	6.5	0.4
Financing Receivable, Allowance for Credit Loss, Recovery	0.2	0	1.3	0
Commercial and Floor Plans [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	52.9	31	27.1	34.2
Provision charged to operating expense	1.9	(3.4)	20.3	(5.2)
Loans Charged-Off	(1.1)	(0.3)	(5.3)	(2.1)
Ending balance	54.1	29	54.1	29
Financing Receivable, Allowance for Credit Loss, Recovery	0.4	1.7	0.8	2.1
Commercial Real Estate Owner Occupied [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	25.2	17.4	13.3	18.3
Provision charged to operating expense	1.4	1.4	6	0.6
Loans Charged-Off	0	(2.2)	(2.2)	(2.3)
Ending balance	26.6	16.6	26.6	16.6
Financing Receivable, Allowance for Credit Loss, Recovery	0	0	0	0
Commercial Real Estate Multi-family [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	54.6	11.8	13.3	11
Provision charged to operating expense	(2.9)	(0.2)	8.5	0.6
Loans Charged-Off	0	0	0	0
Ending balance	33.4	11.6	33.4	11.6
Financing Receivable, Allowance for Credit Loss, Recovery	0.7	0	0.7	0
Commercial real estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	125	52.2	43.9	54.8
Provision charged to operating expense	(10.3)	1	12.4	(1.5)
Loans Charged-Off	0	(2.2)	(5.1)	(2.3)
Ending balance	89.5	51.1	89.5	51.1
Financing Receivable, Allowance for Credit Loss, Recovery	0.7	0.1	0.7	0.1
Land Acquisition And Development Construction Financing Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0.5	1.2	0.5	1.3
Provision charged to operating expense	0.2	(0.4)	(0.6)	(0.6)
Loans Charged-Off	0	(0.1)	(2.7)	(0.1)
Ending balance	0.8	1	0.8	1
Financing Receivable, Allowance for Credit Loss, Recovery	0.1	0.3	0.2	0.4
Residential construction
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3.3	1.4	2.4	1.6
Provision charged to operating expense	0.1	0.2	1	0
Loans Charged-Off	0	(0.1)	0	(0.1)
Ending balance	3.4	1.5	3.4	1.5
Financing Receivable, Allowance for Credit Loss, Recovery	0	0	0	0
Commercial construction
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10.2	7.2	6	7.3
Provision charged to operating expense	4.7	0.9	8.7	0.7
Loans Charged-Off	0	(0.1)	0	(0.1)
Ending balance	14.9	8	14.9	8
Financing Receivable, Allowance for Credit Loss, Recovery	0	0	0	0.1
Construction Loans [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	9.8	8.9	10.2
Provision charged to operating expense	5	0.7	9.1	0.1
Loans Charged-Off	0	(0.3)	(2.7)	(0.3)
Ending balance	19.1	10.5	19.1	10.5
Financing Receivable, Allowance for Credit Loss, Recovery	0.1	0.3	0.2	0.5
Residential Real Estate 1-4 Family [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18.7	11.5	13.4	11.4
Provision charged to operating expense	(0.7)	1.9	4.5	2
Loans Charged-Off	0	0	(0.1)	0
Ending balance	18.2	13.4	18.2	13.4
Financing Receivable, Allowance for Credit Loss, Recovery	0.2	0	0.3	0
Home Equity Line of Credit [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1.4	1.4	1.2	1.4
Provision charged to operating expense	(0.1)	(0.1)	0	(0.1)
Loans Charged-Off	0	0	0	(0.1)
Ending balance	1.5	1.4	1.5	1.4
Financing Receivable, Allowance for Credit Loss, Recovery	0.2	0.1	0.3	0.2
Residential Real Estate [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	20.1	12.9	14.6	12.8
Provision charged to operating expense	(0.8)	1.8	4.5	1.9
Loans Charged-Off	0	0	(0.1)	(0.1)
Ending balance	19.7	14.8	19.7	14.8
Financing Receivable, Allowance for Credit Loss, Recovery	0.4	0.1	0.6	0.2
Agricultural Real Estate Financing Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10.5	2.8	1.9	2.7
Provision charged to operating expense	(5.1)	0.2	1.3	0.3
Loans Charged-Off	(0.1)	0	(0.2)	0
Ending balance	5.4	3	5.4	3
Financing Receivable, Allowance for Credit Loss, Recovery	0.1	0	0.1	0
Real Estate Financing Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	169.6	77.7	69.3	80.5
Provision charged to operating expense	(11.2)	3.7	27.3	0.8
Loans Charged-Off	(0.1)	(2.5)	(8.1)	(2.7)
Ending balance	133.7	79.4	133.7	79.4
Financing Receivable, Allowance for Credit Loss, Recovery	1.3	0.5	1.6	0.8
Consumer Indirect Financing Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	13.5	16	14.3	16.7
Provision charged to operating expense	(0.4)	(0.2)	(0.7)	(0.2)
Loans Charged-Off	(0.8)	(0.8)	(1.7)	(2.1)
Ending balance	13.1	15.8	13.1	15.8
Financing Receivable, Allowance for Credit Loss, Recovery	0.8	0.8	1.2	1.4
Direct consumer
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4.6	4.8	4.6	4.6
Provision charged to operating expense	0.5	0	0.4	0.7
Loans Charged-Off	(0.6)	(0.4)	(1.4)	(1.2)
Ending balance	5	4.6	5	4.6
Financing Receivable, Allowance for Credit Loss, Recovery	0.5	0.2	1.4	0.5
Credit Card Receivable [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	2.3	1.5	2.2	2.6
Provision charged to operating expense	0.7	0.3	1.3	(0.4)
Loans Charged-Off	(0.9)	(0.4)	(1.5)	(1)
Ending balance	2.2	1.6	2.2	1.6
Financing Receivable, Allowance for Credit Loss, Recovery	0.1	0.2	0.2	0.4
Consumer
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	20.4	22.3	21.1	23.9
Provision charged to operating expense	0.8	0.1	1	0.1
Loans Charged-Off	(2.3)	(1.6)	(4.6)	(4.3)
Ending balance	20.3	22	20.3	22
Financing Receivable, Allowance for Credit Loss, Recovery	1.4	1.2	2.8	2.3
Commercial Purpose secured by 1-4 Family [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	5	4.7	4.4	4.7
Provision charged to operating expense	0.4	(0.4)	0.8	(0.6)
Loans Charged-Off	0	(0.1)	0	(0.1)
Ending balance	5.5	4.4	5.5	4.4
Financing Receivable, Allowance for Credit Loss, Recovery	0.1	0.2	0.1	0.4
Commercial Borrower [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0.3	0.3	0.1	0.3
Provision charged to operating expense	0.1	0	0.4	0.2
Loans Charged-Off	(0.1)	(0.1)	(0.2)	(0.3)
Ending balance	0.3	0.3	0.3	0.3
Financing Receivable, Allowance for Credit Loss, Recovery	0	0.1	0	0.1
Commercial Portfolio Segment [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	58.2	36	31.6	39.2
Provision charged to operating expense	2.4	(3.8)	21.5	(5.6)
Loans Charged-Off	(1.2)	(0.5)	(5.5)	(2.5)
Ending balance	59.9	33.7	59.9	33.7
Financing Receivable, Allowance for Credit Loss, Recovery	$ 0.5	$ 2	$ 0.9	$ 2.6

Loans Held for Investment - Nar

Loans Held for Investment - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Receivables [Abstract]
Loans renegotiated in troubled debt restructurings	$ 28,900,000		$ 28,900,000		$ 6,200,000
Troubled restructurings included in non-accrual loans	8,400,000		8,400,000		3,900,000
Loans renegotiated in troubled debt restructurings, accrual loans	20,500,000		20,500,000		2,300,000
Financing receivable, after allowance for credit loss, noncurrent	200,000		200,000		100,000
TDR commitment to lend					0
Troubled debt restructurings	6,400,000		23,600,000
Charge-offs directly related to modifying troubled debt restructurings	0	$ 0	0	$ 0
Balance of defaulted loans under trouble debt restructurings	0		0
Impaired financing receivable, recorded investment	190,800,000		190,800,000
Commitments to purchase or sell	0	0	0	$ 0
Proceeds from sale of loans held-for-investment	0	$ 0
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(10,500,000)		(10,500,000)		(4,400,000)
Derivative Instruments and Hedges, Assets	$ 189,500,000		$ 189,500,000		$ 695,600,000

Loans Held for Investment - S_4

Loans Held for Investment - Schedule of Recorded Investment in Impaired Loans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Provision charged to operating expense	$ 1.7	$ 0	$ (59.6)	$ 5.1
Accounts Receivable, Allowance for Credit Loss	220.4	135.5	220.4	135.5	$ 247.2	$ 122.3	$ 136.6	$ 144.3
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	(1.7)	0	55.6	(4.8)
Balance of defaulted loans under trouble debt restructurings	0		0
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	85.5		85.5			11.7
Total real estate loans
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Provision charged to operating expense	11.2	(3.7)	(27.3)	(0.8)
Accounts Receivable, Allowance for Credit Loss	133.7	79.4	133.7	79.4	169.6	69.3	77.7	80.5
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	64.8		64.8			8.2
Commercial
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Provision charged to operating expense	(2.4)	3.8	(21.5)	5.6
Accounts Receivable, Allowance for Credit Loss	59.9	33.7	59.9	33.7	58.2	31.6	36	39.2
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	10.2		10.2			2.8
Agricultural
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Provision charged to operating expense	(6.3)	0	(5.8)	0.1
Accounts Receivable, Allowance for Credit Loss	6.5	$ 0.4	6.5	$ 0.4	$ (1)	0.3	$ 0.6	$ 0.7
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	10.5		10.5			0.7
Business Assets Pledged as Collateral [Member]
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	5.8		5.8			3
Business Assets Pledged as Collateral [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1.2		1.2			1.2
Business Assets Pledged as Collateral [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	4.6		4.6			1.8
Business Assets Pledged as Collateral [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0		0			0
Real Property Pledged as Collateral [Member]
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	79.7		79.7			8.7
Real Property Pledged as Collateral [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	63.6		63.6			7
Real Property Pledged as Collateral [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	5.6		5.6			1
Real Property Pledged as Collateral [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	10.5		10.5			0.7
Other Property [Member]
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0		0			0
Other Property [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0		0			0
Other Property [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0		0			0
Other Property [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	$ 0		$ 0			$ 0

Loans Held for Investment - S_5

Loans Held for Investment - Schedule of Contractual Aging of Loans by Portfolio (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Nonaccrual, Interest Income	$ 0	$ 0
Impaired Financing Receivable, Interest Income, Accrual Method	0		$ 0	$ 0	$ 0
Accrued interest reversal				0
Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	7,900,000			7,900,000		$ 2,700,000
Nonaccrual loans	29,700,000			29,700,000		8,000,000
Total Loans	7,857,700,000			7,857,700,000		3,971,500,000
Land acquisition & development
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	800,000			800,000		200,000
Nonaccrual loans	4,100,000			4,100,000		700,000
Total Loans	355,700,000			355,700,000		247,800,000
Residential construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,400,000			1,400,000		4,200,000
Nonaccrual loans	0			0		0
Total Loans	444,800,000			444,800,000		262,000,000
Commercial construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	10,700,000			10,700,000		0
Nonaccrual loans	0			0		0
Total Loans	959,000,000			959,000,000		498,000,000
Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	12,900,000			12,900,000		4,400,000
Nonaccrual loans	4,100,000			4,100,000		700,000
Total Loans	1,759,500,000			1,759,500,000		1,007,800,000
Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	5,700,000			5,700,000		3,900,000
Nonaccrual loans	5,000,000			5,000,000		2,900,000
Total Loans	2,060,400,000			2,060,400,000		1,538,200,000
Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,400,000			2,400,000		2,100,000
Nonaccrual loans	37,900,000			37,900,000		4,900,000
Total Loans	821,500,000			821,500,000		213,900,000
Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	28,900,000			28,900,000		13,100,000
Nonaccrual loans	76,700,000			76,700,000		16,500,000
Total Loans	12,499,100,000			12,499,100,000		6,731,400,000
Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	6,900,000			6,900,000		6,900,000
Nonaccrual loans	1,800,000			1,800,000		1,700,000
Total Loans	733,900,000			733,900,000		737,600,000
Direct and advance lines
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	800,000			800,000		800,000
Nonaccrual loans	200,000			200,000		100,000
Total Loans	157,300,000			157,300,000		129,200,000
Credit card
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,100,000			1,100,000		1,300,000
Nonaccrual loans	0			0		0
Total Loans	74,800,000			74,800,000		64,900,000
Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	8,800,000			8,800,000		9,000,000
Nonaccrual loans	2,000,000			2,000,000		1,800,000
Total Loans	966,000,000			966,000,000		931,700,000
Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	11,500,000			11,500,000		6,700,000
Nonaccrual loans	13,900,000			13,900,000		5,000,000
Total Loans	3,036,000,000			3,036,000,000		1,475,500,000
Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	10,100,000			10,100,000		700,000
Nonaccrual loans	14,400,000			14,400,000		1,600,000
Total Loans	672,000,000			672,000,000		203,900,000
Other, including overdrafts
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process						0
Nonaccrual loans						0
Total Loans	0			0		1,500,000
Loans And Leases Held For Investment [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	59,300,000			59,300,000		29,500,000
Nonaccrual loans	107,000,000			107,000,000		24,900,000
Total Loans	17,173,100,000			17,173,100,000		9,344,000,000
30 to 59 Days Past Due | Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	5,100,000			5,100,000		1,100,000
30 to 59 Days Past Due | Land acquisition & development
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	700,000			700,000		200,000
30 to 59 Days Past Due | Residential construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,000,000			1,000,000		4,200,000
30 to 59 Days Past Due | Commercial construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	10,700,000			10,700,000		0
30 to 59 Days Past Due | Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	12,400,000			12,400,000		4,400,000
30 to 59 Days Past Due | Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	3,200,000			3,200,000		3,000,000
30 to 59 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,100,000			2,100,000		1,900,000
30 to 59 Days Past Due | Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	22,800,000			22,800,000		10,400,000
30 to 59 Days Past Due | Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	5,300,000			5,300,000		5,100,000
30 to 59 Days Past Due | Direct and advance lines
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	600,000			600,000		500,000
30 to 59 Days Past Due | Credit card
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	600,000			600,000		600,000
30 to 59 Days Past Due | Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	6,500,000			6,500,000		6,200,000
30 to 59 Days Past Due | Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	8,400,000			8,400,000		4,900,000
30 to 59 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	10,000,000			10,000,000		700,000
30 to 59 Days Past Due | Other, including overdrafts
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process						0
30 to 59 Days Past Due | Loans And Leases Held For Investment [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	47,700,000			47,700,000		22,200,000
60 to 89 Days Past Due | Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,100,000			2,100,000		1,000,000
60 to 89 Days Past Due | Land acquisition & development
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	100,000			100,000		0
60 to 89 Days Past Due | Residential construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	400,000			400,000		0
60 to 89 Days Past Due | Commercial construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
60 to 89 Days Past Due | Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	500,000			500,000		0
60 to 89 Days Past Due | Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,100,000			2,100,000		800,000
60 to 89 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		200,000
60 to 89 Days Past Due | Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	4,700,000			4,700,000		2,000,000
60 to 89 Days Past Due | Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,400,000			1,400,000		1,400,000
60 to 89 Days Past Due | Direct and advance lines
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	200,000			200,000		200,000
60 to 89 Days Past Due | Credit card
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	200,000			200,000		200,000
60 to 89 Days Past Due | Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,800,000			1,800,000		1,800,000
60 to 89 Days Past Due | Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,100,000			2,100,000		700,000
60 to 89 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	100,000			100,000		0
60 to 89 Days Past Due | Other, including overdrafts
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process						0
60 to 89 Days Past Due | Loans And Leases Held For Investment [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	8,700,000			8,700,000		4,500,000
Equal to or Greater than 90 Days Past Due | Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	700,000			700,000		600,000
Equal to or Greater than 90 Days Past Due | Land acquisition & development
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
Equal to or Greater than 90 Days Past Due | Residential construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
Equal to or Greater than 90 Days Past Due | Commercial construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
Equal to or Greater than 90 Days Past Due | Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
Equal to or Greater than 90 Days Past Due | Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	400,000			400,000		100,000
Equal to or Greater than 90 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	300,000			300,000		0
Equal to or Greater than 90 Days Past Due | Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,400,000			1,400,000		700,000
Equal to or Greater than 90 Days Past Due | Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	200,000			200,000		400,000
Equal to or Greater than 90 Days Past Due | Direct and advance lines
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		100,000
Equal to or Greater than 90 Days Past Due | Credit card
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	300,000			300,000		500,000
Equal to or Greater than 90 Days Past Due | Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	500,000			500,000		1,000,000
Equal to or Greater than 90 Days Past Due | Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,000,000			1,000,000		1,100,000
Equal to or Greater than 90 Days Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	0			0		0
Equal to or Greater than 90 Days Past Due | Other, including overdrafts
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process						0
Equal to or Greater than 90 Days Past Due | Loans And Leases Held For Investment [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,900,000			2,900,000		2,800,000
Financial Asset, Not Past Due | Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	7,820,100,000			7,820,100,000		3,960,800,000
Financial Asset, Not Past Due | Land acquisition & development
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	350,800,000			350,800,000		246,900,000
Financial Asset, Not Past Due | Residential construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	443,400,000			443,400,000		257,800,000
Financial Asset, Not Past Due | Commercial construction
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	948,300,000			948,300,000		498,000,000
Financial Asset, Not Past Due | Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	1,742,500,000			1,742,500,000		1,002,700,000
Financial Asset, Not Past Due | Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	2,049,700,000			2,049,700,000		1,531,400,000
Financial Asset, Not Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	781,200,000			781,200,000		206,900,000
Financial Asset, Not Past Due | Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	12,393,500,000			12,393,500,000		6,701,800,000
Financial Asset, Not Past Due | Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	725,200,000			725,200,000		729,000,000
Financial Asset, Not Past Due | Direct and advance lines
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	156,300,000			156,300,000		128,300,000
Financial Asset, Not Past Due | Credit card
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	73,700,000			73,700,000		63,600,000
Financial Asset, Not Past Due | Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	955,200,000			955,200,000		920,900,000
Financial Asset, Not Past Due | Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	3,010,600,000			3,010,600,000		1,463,800,000
Financial Asset, Not Past Due | Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	647,500,000			647,500,000		201,600,000
Financial Asset, Not Past Due | Other, including overdrafts
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process						1,500,000
Financial Asset, Not Past Due | Loans And Leases Held For Investment [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Loan in Process	$ 17,006,800,000			$ 17,006,800,000		$ 9,289,600,000

Loans Held for Investment - S_6

Loans Held for Investment - Schedule of Troubled Debt Restructurings (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($) note	Jun. 30, 2022 USD ($) note
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note	4	9
Troubled debt restructurings	$ 6.4	$ 23.6
Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	3.2
Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0.1	13.7
Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	$ 6.3	$ 6.7
Commercial Real Estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note	1	3
Troubled debt restructurings	$ 0.2	$ 7.6
Commercial Real Estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	3.2
Commercial Real Estate | Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	4.2
Commercial Real Estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Commercial Real Estate | Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	$ 0.2	$ 0.2
Residential
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note	1	2
Troubled debt restructurings	$ 0.1	$ 0.6
Residential | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Residential | Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0.1	0.6
Residential | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Residential | Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	$ 0	$ 0
Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note		1
Troubled debt restructurings		$ 8.9
Agricultural | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings		0
Agricultural | Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings		8.9
Agricultural | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings		0
Agricultural | Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings		$ 0
Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note	1	2
Troubled debt restructurings	$ 0.2	$ 0.6
Commercial | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Commercial | Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Commercial | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Commercial | Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	$ 0.2	$ 0.6
Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | note	1	1
Troubled debt restructurings	$ 5.9	$ 5.9
Agricultural | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Agricultural | Extension of term or amortization schedule
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Agricultural | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	0	0
Agricultural | Other Loan Restructuring Modification
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings	$ 5.9	$ 5.9

Loans Held for Investment - S_7

Loans Held for Investment - Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Impaired financing receivable, recorded investment	$ 190,800,000		$ 190,800,000
Commitments to purchase or sell	0	$ 0	0	$ 0
Proceeds from sale of loans held-for-investment	0	$ 0
Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	468,200,000		468,200,000		$ 512,000,000
2021	855,000,000		855,000,000		470,600,000
2020	704,800,000		704,800,000		242,300,000
2019	573,300,000		573,300,000		151,100,000
2018	318,400,000		318,400,000		77,300,000
Prior	698,200,000		698,200,000		425,000,000
Revolving Loans Amortized Cost Basis	30,400,000		30,400,000		15,300,000
Total	3,648,300,000		3,648,300,000		1,893,600,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	7,857,700,000		7,857,700,000		3,971,500,000
Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	79,100,000		79,100,000		113,800,000
2021	155,800,000		155,800,000		41,800,000
2020	34,000,000		34,000,000		34,200,000
2019	26,100,000		26,100,000		15,400,000
2018	15,400,000		15,400,000		20,200,000
Prior	32,600,000		32,600,000		21,200,000
Revolving Loans Amortized Cost Basis	12,700,000		12,700,000		1,200,000
Total	355,700,000		355,700,000		247,800,000
Loans held for investment	355,700,000		355,700,000		247,800,000
Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	73,100,000		73,100,000		112,400,000
2021	138,800,000		138,800,000		7,400,000
2020	400,000		400,000		13,700,000
2019	9,700,000		9,700,000		900,000
2018	800,000		800,000		400,000
Prior	6,600,000		6,600,000		0
Revolving Loans Amortized Cost Basis	215,400,000		215,400,000		127,200,000
Total	444,800,000		444,800,000		262,000,000
Loans held for investment	444,800,000		444,800,000		262,000,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	198,000,000		198,000,000		209,700,000
2021	432,000,000		432,000,000		141,400,000
2020	210,700,000		210,700,000		118,800,000
2019	108,900,000		108,900,000		27,600,000
2018	1,900,000		1,900,000		0
Prior	0		0		500,000
Revolving Loans Amortized Cost Basis	7,500,000		7,500,000		0
Total	959,000,000		959,000,000		498,000,000
Loans held for investment	959,000,000		959,000,000		498,000,000
Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,060,400,000		2,060,400,000		1,538,200,000
Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,759,500,000		1,759,500,000		1,007,800,000
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	117,400,000		117,400,000		62,400,000
2021	203,200,000		203,200,000		38,600,000
2020	131,600,000		131,600,000		37,300,000
2019	75,800,000		75,800,000		23,300,000
2018	85,600,000		85,600,000		13,200,000
Prior	155,600,000		155,600,000		33,300,000
Revolving Loans Amortized Cost Basis	52,300,000		52,300,000		5,800,000
Total	821,500,000		821,500,000		213,900,000
Loans held for investment	821,500,000		821,500,000		213,900,000
Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	12,499,100,000		12,499,100,000		6,731,400,000
Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	164,900,000		164,900,000		273,100,000
2021	219,500,000		219,500,000		209,100,000
2020	162,500,000		162,500,000		108,700,000
2019	80,100,000		80,100,000		64,200,000
2018	46,400,000		46,400,000		37,100,000
Prior	60,500,000		60,500,000		45,400,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	733,900,000		733,900,000		737,600,000
Loans held for investment	733,900,000		733,900,000		737,600,000
Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	31,700,000		31,700,000		42,600,000
2021	41,400,000		41,400,000		27,900,000
2020	24,700,000		24,700,000		15,000,000
2019	12,600,000		12,600,000		13,400,000
2018	9,600,000		9,600,000		5,800,000
Prior	11,400,000		11,400,000		7,600,000
Revolving Loans Amortized Cost Basis	25,900,000		25,900,000		16,900,000
Total	157,300,000		157,300,000		129,200,000
Loans held for investment	157,300,000		157,300,000		129,200,000
Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	192,200,000		192,200,000		139,600,000
Loans held for investment	74,800,000		74,800,000		64,900,000
Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	966,000,000		966,000,000		931,700,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,036,000,000		3,036,000,000		1,475,500,000
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022					40,200,000
2021					21,000,000
2020					9,700,000
2019					8,300,000
2018					2,700,000
Prior					2,000,000
Revolving Loans Amortized Cost Basis					118,500,000
Total					202,400,000
Loans held for investment	672,000,000		672,000,000		203,900,000
Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	451,900,000		451,900,000		457,800,000
2021	805,200,000		805,200,000		322,400,000
2020	570,200,000		570,200,000		241,200,000
2019	320,100,000		320,100,000		163,800,000
2018	255,500,000		255,500,000		100,700,000
Prior	928,700,000		928,700,000		356,600,000
Revolving Loans Amortized Cost Basis	25,800,000		25,800,000		14,200,000
Total	3,357,400,000		3,357,400,000		1,656,700,000
Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	152,300,000		152,300,000		129,100,000
2021	212,800,000		212,800,000		118,600,000
2020	222,800,000		222,800,000		43,900,000
2019	55,200,000		55,200,000		15,400,000
2018	82,700,000		82,700,000		36,000,000
Prior	123,000,000		123,000,000		76,700,000
Revolving Loans Amortized Cost Basis	3,200,000		3,200,000		1,500,000
Total	852,000,000		852,000,000		421,200,000
Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	338,600,000		338,600,000		396,300,000
2021	460,900,000		460,900,000		179,900,000
2020	263,000,000		263,000,000		96,900,000
2019	158,000,000		158,000,000		76,900,000
2018	155,000,000		155,000,000		50,700,000
Prior	218,400,000		218,400,000		97,700,000
Revolving Loans Amortized Cost Basis	855,700,000		855,700,000		234,300,000
Total	2,449,600,000		2,449,600,000		1,132,700,000
Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	107,100,000		107,100,000		96,200,000
2021	149,100,000		149,100,000		56,400,000
2020	71,700,000		71,700,000		28,600,000
2019	33,600,000		33,600,000		24,200,000
2018	34,900,000		34,900,000		15,600,000
Prior	49,500,000		49,500,000		34,100,000
Revolving Loans Amortized Cost Basis	25,100,000		25,100,000		14,500,000
Total	471,000,000		471,000,000		269,600,000
Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	129,000,000		129,000,000
2021	104,800,000		104,800,000
2020	42,900,000		42,900,000
2019	15,600,000		15,600,000
2018	15,600,000		15,600,000
Prior	3,100,000		3,100,000
Revolving Loans Amortized Cost Basis	359,000,000		359,000,000
Total	670,000,000		670,000,000
Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	83,600,000		83,600,000		360,900,000
2021	448,600,000		448,600,000		477,300,000
2020	563,600,000		563,600,000		74,700,000
2019	106,100,000		106,100,000		27,500,000
2018	34,300,000		34,300,000		25,900,000
Prior	298,500,000		298,500,000		177,300,000
Revolving Loans Amortized Cost Basis	300,000		300,000		0
Total	1,535,000,000		1,535,000,000		1,143,600,000
Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	10,200,000		10,200,000		11,400,000
2021	10,100,000		10,100,000		7,000,000
2020	5,800,000		5,800,000		4,000,000
2019	3,900,000		3,900,000		4,800,000
2018	6,500,000		6,500,000		4,200,000
Prior	20,800,000		20,800,000		12,500,000
Revolving Loans Amortized Cost Basis	468,100,000		468,100,000		350,700,000
Total	525,400,000		525,400,000		394,600,000
Pass | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	458,600,000		458,600,000		507,900,000
2021	817,200,000		817,200,000		452,200,000
2020	677,900,000		677,900,000		237,900,000
2019	536,000,000		536,000,000		150,400,000
2018	251,200,000		251,200,000		76,300,000
Prior	641,700,000		641,700,000		409,000,000
Revolving Loans Amortized Cost Basis	30,400,000		30,400,000		15,300,000
Total	3,413,000,000		3,413,000,000		1,849,000,000
Pass | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	79,100,000		79,100,000		113,000,000
2021	151,900,000		151,900,000		41,500,000
2020	33,800,000		33,800,000		34,200,000
2019	26,100,000		26,100,000		14,800,000
2018	15,200,000		15,200,000		19,800,000
Prior	31,700,000		31,700,000		20,800,000
Revolving Loans Amortized Cost Basis	12,700,000		12,700,000		1,200,000
Total	350,500,000		350,500,000		245,300,000
Pass | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	73,100,000		73,100,000		112,400,000
2021	138,800,000		138,800,000		7,000,000
2020	400,000		400,000		13,700,000
2019	9,700,000		9,700,000		900,000
2018	800,000		800,000		0
Prior	6,200,000		6,200,000		0
Revolving Loans Amortized Cost Basis	215,400,000		215,400,000		127,200,000
Total	444,400,000		444,400,000		261,200,000
Pass | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	198,000,000		198,000,000		209,700,000
2021	432,000,000		432,000,000		141,400,000
2020	187,600,000		187,600,000		118,800,000
2019	87,200,000		87,200,000		27,600,000
2018	1,900,000		1,900,000		0
Prior	0		0		500,000
Revolving Loans Amortized Cost Basis	7,500,000		7,500,000		0
Total	914,200,000		914,200,000		498,000,000
Pass | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	112,600,000		112,600,000		58,300,000
2021	182,200,000		182,200,000		36,900,000
2020	122,200,000		122,200,000		35,100,000
2019	70,000,000		70,000,000		22,600,000
2018	53,900,000		53,900,000		11,800,000
Prior	134,100,000		134,100,000		28,100,000
Revolving Loans Amortized Cost Basis	29,800,000		29,800,000		4,900,000
Total	704,800,000		704,800,000		197,700,000
Pass | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022					35,100,000
2021					16,200,000
2020					9,000,000
2019					5,400,000
2018					2,100,000
Prior					1,600,000
Revolving Loans Amortized Cost Basis					108,900,000
Total					178,300,000
Pass | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	438,600,000		438,600,000		452,700,000
2021	793,800,000		793,800,000		314,900,000
2020	564,200,000		564,200,000		235,000,000
2019	307,800,000		307,800,000		151,000,000
2018	239,700,000		239,700,000		94,500,000
Prior	887,200,000		887,200,000		322,500,000
Revolving Loans Amortized Cost Basis	25,100,000		25,100,000		14,200,000
Total	3,256,400,000		3,256,400,000		1,584,800,000
Pass | Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	152,300,000		152,300,000		129,100,000
2021	212,800,000		212,800,000		118,600,000
2020	185,300,000		185,300,000		43,900,000
2019	54,000,000		54,000,000		15,400,000
2018	36,500,000		36,500,000		36,000,000
Prior	122,700,000		122,700,000		76,700,000
Revolving Loans Amortized Cost Basis	3,200,000		3,200,000		1,500,000
Total	766,800,000		766,800,000		421,200,000
Pass | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	318,500,000		318,500,000		394,200,000
2021	447,600,000		447,600,000		165,700,000
2020	256,900,000		256,900,000		94,500,000
2019	151,300,000		151,300,000		73,500,000
2018	149,100,000		149,100,000		47,100,000
Prior	202,600,000		202,600,000		91,300,000
Revolving Loans Amortized Cost Basis	821,700,000		821,700,000		224,700,000
Total	2,347,700,000		2,347,700,000		1,091,000,000
Pass | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	106,500,000		106,500,000		94,900,000
2021	147,200,000		147,200,000		55,000,000
2020	69,900,000		69,900,000		27,800,000
2019	32,700,000		32,700,000		23,100,000
2018	32,400,000		32,400,000		15,300,000
Prior	47,600,000		47,600,000		32,200,000
Revolving Loans Amortized Cost Basis	25,000,000		25,000,000		14,400,000
Total	461,300,000		461,300,000		262,700,000
Pass | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	103,100,000		103,100,000
2021	91,100,000		91,100,000
2020	37,200,000		37,200,000
2019	13,400,000		13,400,000
2018	10,600,000		10,600,000
Prior	1,200,000		1,200,000
Revolving Loans Amortized Cost Basis	343,800,000		343,800,000
Total	600,400,000		600,400,000
Other Assets Especially Mentioned | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	6,100,000		6,100,000		200,000
2021	25,000,000		25,000,000		3,100,000
2020	1,900,000		1,900,000		2,100,000
2019	18,000,000		18,000,000		0
2018	33,800,000		33,800,000		0
Prior	24,500,000		24,500,000		3,600,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	109,300,000		109,300,000		9,000,000
Other Assets Especially Mentioned | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		0
2021	0		0		100,000
2020	0		0		0
2019	0		0		0
2018	200,000		200,000		100,000
Prior	300,000		300,000		300,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	500,000		500,000		500,000
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	0		0
2020	23,100,000		23,100,000
2019	0		0
2018	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	23,100,000		23,100,000
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	1,500,000		1,500,000		100,000
2021	2,500,000		2,500,000		1,300,000
2020	2,300,000		2,300,000		1,200,000
2019	1,800,000		1,800,000		100,000
2018	9,700,000		9,700,000		100,000
Prior	5,900,000		5,900,000		900,000
Revolving Loans Amortized Cost Basis	9,900,000		9,900,000		900,000
Total	33,600,000		33,600,000		4,600,000
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022					200,000
2021					4,100,000
2020					100,000
2019					400,000
2018					600,000
Prior					300,000
Revolving Loans Amortized Cost Basis					7,000,000
Total					12,700,000
Other Assets Especially Mentioned | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	3,000,000		3,000,000		1,300,000
2021	5,600,000		5,600,000		3,200,000
2020	3,000,000		3,000,000		1,500,000
2019	7,100,000		7,100,000		7,400,000
2018	2,100,000		2,100,000		3,500,000
Prior	12,700,000		12,700,000		13,800,000
Revolving Loans Amortized Cost Basis	300,000		300,000		0
Total	33,800,000		33,800,000		30,700,000
Other Assets Especially Mentioned | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	6,600,000		6,600,000		800,000
2021	7,100,000		7,100,000		11,400,000
2020	2,500,000		2,500,000		800,000
2019	4,100,000		4,100,000		800,000
2018	2,300,000		2,300,000		3,000,000
Prior	6,100,000		6,100,000		2,300,000
Revolving Loans Amortized Cost Basis	22,400,000		22,400,000		7,000,000
Total	51,100,000		51,100,000		26,100,000
Other Assets Especially Mentioned | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	200,000		200,000		0
2021	400,000		400,000		200,000
2020	600,000		600,000		200,000
2019	600,000		600,000		500,000
2018	1,900,000		1,900,000		100,000
Prior	600,000		600,000		600,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	4,300,000		4,300,000		1,600,000
Other Assets Especially Mentioned | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	3,100,000		3,100,000
2021	2,200,000		2,200,000
2020	600,000		600,000
2019	1,300,000		1,300,000
2018	700,000		700,000
Prior	300,000		300,000
Revolving Loans Amortized Cost Basis	10,900,000		10,900,000
Total	19,100,000		19,100,000
Substandard | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	3,200,000		3,200,000		3,900,000
2021	12,800,000		12,800,000		15,300,000
2020	25,000,000		25,000,000		2,300,000
2019	17,700,000		17,700,000		700,000
2018	31,600,000		31,600,000		1,000,000
Prior	32,000,000		32,000,000		12,400,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	122,300,000		122,300,000		35,600,000
Substandard | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		800,000
2021	700,000		700,000		200,000
2020	200,000		200,000		0
2019	0		0		600,000
2018	0		0		300,000
Prior	600,000		600,000		100,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	1,500,000		1,500,000		2,000,000
Substandard | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		0
2021	0		0		400,000
2020	0		0		0
2019	0		0		0
2018	0		0		400,000
Prior	400,000		400,000		0
Revolving Loans Amortized Cost Basis	0		0		0
Total	400,000		400,000		800,000
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	0		0
2020	0		0
2019	21,700,000		21,700,000
2018	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	21,700,000		21,700,000
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	3,300,000		3,300,000		4,000,000
2021	17,600,000		17,600,000		400,000
2020	4,000,000		4,000,000		1,000,000
2019	3,200,000		3,200,000		600,000
2018	22,000,000		22,000,000		1,300,000
Prior	13,700,000		13,700,000		4,300,000
Revolving Loans Amortized Cost Basis	12,600,000		12,600,000		0
Total	76,400,000		76,400,000		11,600,000
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022					4,900,000
2021					700,000
2020					600,000
2019					2,500,000
2018					0
Prior					100,000
Revolving Loans Amortized Cost Basis					2,600,000
Total					11,400,000
Substandard | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	10,300,000		10,300,000		3,800,000
2021	2,900,000		2,900,000		4,300,000
2020	3,000,000		3,000,000		4,700,000
2019	5,200,000		5,200,000		5,400,000
2018	4,300,000		4,300,000		2,700,000
Prior	26,800,000		26,800,000		20,300,000
Revolving Loans Amortized Cost Basis	400,000		400,000		0
Total	52,900,000		52,900,000		41,200,000
Substandard | Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	0		0
2020	37,500,000		37,500,000
2019	1,200,000		1,200,000
2018	46,200,000		46,200,000
Prior	300,000		300,000
Revolving Loans Amortized Cost Basis	0		0
Total	85,200,000		85,200,000
Substandard | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	13,500,000		13,500,000		1,300,000
2021	1,500,000		1,500,000		2,800,000
2020	3,400,000		3,400,000		1,600,000
2019	2,600,000		2,600,000		2,600,000
2018	3,600,000		3,600,000		600,000
Prior	8,100,000		8,100,000		4,100,000
Revolving Loans Amortized Cost Basis	11,600,000		11,600,000		2,600,000
Total	44,300,000		44,300,000		15,600,000
Substandard | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	400,000		400,000		1,300,000
2021	1,300,000		1,300,000		1,200,000
2020	1,200,000		1,200,000		600,000
2019	300,000		300,000		600,000
2018	600,000		600,000		200,000
Prior	1,300,000		1,300,000		1,300,000
Revolving Loans Amortized Cost Basis	100,000		100,000		100,000
Total	5,200,000		5,200,000		5,300,000
Substandard | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	22,800,000		22,800,000
2021	6,900,000		6,900,000
2020	5,100,000		5,100,000
2019	900,000		900,000
2018	1,800,000		1,800,000
Prior	700,000		700,000
Revolving Loans Amortized Cost Basis	4,300,000		4,300,000
Total	42,500,000		42,500,000
Doubtful | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	300,000		300,000
2021	0		0
2020	0		0
2019	1,600,000		1,600,000
2018	1,800,000		1,800,000
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	3,700,000		3,700,000
Doubtful | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	3,200,000		3,200,000
2020	0		0
2019	0		0
2018	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	3,200,000		3,200,000
Doubtful | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	900,000		900,000
2020	3,100,000		3,100,000
2019	800,000		800,000
2018	0		0
Prior	1,900,000		1,900,000
Revolving Loans Amortized Cost Basis	0		0
Total	6,700,000		6,700,000
Doubtful | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	2,900,000		2,900,000
2020	0		0
2019	0		0
2018	9,400,000		9,400,000
Prior	2,000,000		2,000,000
Revolving Loans Amortized Cost Basis	0		0
Total	14,300,000		14,300,000
Doubtful | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	4,700,000		4,700,000
2020	200,000		200,000
2019	0		0
2018	0		0
Prior	1,600,000		1,600,000
Revolving Loans Amortized Cost Basis	0		0
Total	6,500,000		6,500,000
Doubtful | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	200,000		200,000
2020	0		0
2019	0		0
2018	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	200,000		200,000
Doubtful | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0
2021	4,600,000		4,600,000
2020	0		0
2019	0		0
2018	2,500,000		2,500,000
Prior	900,000		900,000
Revolving Loans Amortized Cost Basis	0		0
Total	8,000,000		8,000,000
Performing | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	164,900,000		164,900,000		272,600,000
2021	218,800,000		218,800,000		208,600,000
2020	162,100,000		162,100,000		108,300,000
2019	79,800,000		79,800,000		64,000,000
2018	46,200,000		46,200,000		37,000,000
Prior	60,100,000		60,100,000		45,000,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	731,900,000		731,900,000		735,500,000
Performing | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	31,700,000		31,700,000		42,500,000
2021	41,400,000		41,400,000		27,900,000
2020	24,700,000		24,700,000		15,000,000
2019	12,600,000		12,600,000		13,300,000
2018	9,600,000		9,600,000		5,800,000
Prior	11,300,000		11,300,000		7,600,000
Revolving Loans Amortized Cost Basis	25,900,000		25,900,000		16,900,000
Total	157,200,000		157,200,000		129,000,000
Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	191,400,000		191,400,000		139,000,000
Performing | Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	83,600,000		83,600,000		360,900,000
2021	448,600,000		448,600,000		477,000,000
2020	563,500,000		563,500,000		74,700,000
2019	106,000,000		106,000,000		27,500,000
2018	34,000,000		34,000,000		25,700,000
Prior	296,200,000		296,200,000		176,500,000
Revolving Loans Amortized Cost Basis	300,000		300,000		0
Total	1,532,200,000		1,532,200,000		1,142,300,000
Performing | Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	9,900,000		9,900,000		11,100,000
2021	9,700,000		9,700,000		7,000,000
2020	5,800,000		5,800,000		3,700,000
2019	3,800,000		3,800,000		4,800,000
2018	6,300,000		6,300,000		3,600,000
Prior	19,400,000		19,400,000		12,000,000
Revolving Loans Amortized Cost Basis	468,000,000		468,000,000		350,700,000
Total	522,900,000		522,900,000		392,900,000
Nonperforming | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		500,000
2021	700,000		700,000		500,000
2020	400,000		400,000		400,000
2019	300,000		300,000		200,000
2018	200,000		200,000		100,000
Prior	400,000		400,000		400,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	2,000,000		2,000,000		2,100,000
Nonperforming | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		100,000
2021	0		0		0
2020	0		0		0
2019	0		0		100,000
2018	0		0		0
Prior	100,000		100,000		0
Revolving Loans Amortized Cost Basis	0		0		0
Total	100,000		100,000		200,000
Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	800,000		800,000		600,000
Nonperforming | Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		0
2021	0		0		300,000
2020	100,000		100,000		0
2019	100,000		100,000		0
2018	300,000		300,000		200,000
Prior	2,300,000		2,300,000		800,000
Revolving Loans Amortized Cost Basis	0		0		0
Total	2,800,000		2,800,000		1,300,000
Nonperforming | Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	300,000		300,000		300,000
2021	400,000		400,000		0
2020	0		0		300,000
2019	100,000		100,000		0
2018	200,000		200,000		600,000
Prior	1,400,000		1,400,000		500,000
Revolving Loans Amortized Cost Basis	100,000		100,000		0
Total	2,500,000		2,500,000		1,700,000
Agriculture Portfolio Segment [Member] | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	2,000,000		2,000,000		1,500,000
Agriculture Portfolio Segment [Member] | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	2,000,000		2,000,000		1,500,000
Agriculture Portfolio Segment [Member] | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	0		0		0
Commercial | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	115,400,000		115,400,000		73,200,000
Commercial | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	114,900,000		114,900,000		73,100,000
Commercial | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	500,000		500,000		100,000
Total consumer loans | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	74,800,000		74,800,000		64,900,000
Total consumer loans | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	74,500,000		74,500,000		64,400,000
Total consumer loans | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2022	$ 300,000		$ 300,000		$ 500,000

Loans Held for Investment - S_8

Loans Held for Investment - Schedule of PCD Loans (Details) $ in Millions	Feb. 01, 2022 USD ($)
Receivables [Abstract]
Purchase price (initial fair value)	$ 623.3
Allowance for credit losses	(298.2)
Non-credit discount at acquisition	57.7
Par value (unpaid principal balance)	979.2
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses, Decreases	238.7
Business Combination, Impact On Purchased Credit Deteriorated Loans	59.5
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Difference Between Amortized Cost Basis And Unpaid Principal Balance	39.6
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Interest Applied To Principal	$ 18.1

Other Real Estate Owned (Detail

Other Real Estate Owned (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance	$ 17.5	$ 2.2	$ 2	$ 2.5
Acquired through acquisition	0	0	15.8	0
Additions	0.1	0	0.1	0.3
Dispositions	(0.8)	(0.2)	(1.1)	(0.8)
Ending balance	16.8	$ 2	16.8	$ 2
Carrying values of foreclosed residential real estate properties	0		0
Consumer mortgage loans collateralized by residential real estate property in the process of foreclosure	$ 0		$ 0

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	$ 2,021.9	$ 1,691.2
Derivative Asset, Estimated Fair Value	24.8	28.1
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	1,867.2	1,103.9
Derivative Liabilities, Estimated Fair Value		18.2
Interest rate swap contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	0	87.6
Derivative Asset, Estimated Fair Value	0	0.1
Not Designated as Hedging Instrument | Interest rate swap contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	1,758.7	913.9
Derivative Asset, Estimated Fair Value	14.3	22.2
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	1,758.7	913.9
Derivative Liabilities, Estimated Fair Value	99.2	18.1
Not Designated as Hedging Instrument | Interest rate lock commitments
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	28.6	77.3
Derivative Asset, Estimated Fair Value	0.2	1.8
Not Designated as Hedging Instrument | Forward loan sales contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	34.6	0
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	0	102.4
Derivative Liabilities, Estimated Fair Value	0	0
Designated as Hedging Instrument [Member] | Interest rate swap contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	200	700
Derivative Asset, Estimated Fair Value	$ 10.3	$ 4.1

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities - Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Financial Assets
Gross Amounts Recognized	$ 24.8		$ 24.8		$ 28.1
Gross Amounts Offset in the Balance Sheet	0		0		0
Net Amounts in the Balance Sheet	24.8		24.8		28.1
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	23.7		23.7		8
Net Amount	1.1		1.1		20.1
Derivative Assets (Liabilities), at Fair Value, Net	24.8		24.8
Financial Liabilities
Gross Amounts Recognized	99.4		99.4		18.2
Gross Amounts Offset in the Balance Sheet	0		0		0
Net Amounts in the Balance Sheet	99.4		99.4		18.2
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	0		0		0
Net Amount	99.4		99.4		18.2
Repurchase agreements
Gross Amounts Recognized					1,051.1
Gross Amounts Offset in the Balance Sheet					0
Net Amounts in the Balance Sheet	1,234.7		1,234.7		1,051.1
Financial Instruments					0
Fair Value of Financial Collateral in the Balance Sheet					1,051.1
Net Amount					0
Total assets and liabilities
Gross Amounts Recognized	1,334.1		1,334.1		1,069.3
Gross Amounts Offset in the Balance Sheet					0
Net Amounts in the Balance Sheet	1,334.1		1,334.1		1,069.3
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	1,234.7		1,234.7		1,051.1
Net Amount	99.4		99.4		18.2
Derivative Liability, Notional Amount	1,867.2		1,867.2		1,103.9
Not Designated as Hedging Instrument
Total assets and liabilities
Amount of net gains recognized in mortgage banking revenues	1	$ 0.2	1.5	$ 0.5
Interest Rate Swap
Financial Assets
Gross Amounts Recognized	24.6		24.6		26.3
Gross Amounts Offset in the Balance Sheet	0		0		0
Net Amounts in the Balance Sheet	24.6		24.6		26.3
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	23.7		23.7		8
Net Amount	0.9		0.9		18.3
Financial Liabilities
Gross Amounts Recognized	99.2		99.2		18.2
Gross Amounts Offset in the Balance Sheet	0		0		0
Net Amounts in the Balance Sheet	99.2		99.2		18.2
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	0		0		0
Net Amount	99.2		99.2		18.2
Interest Rate Swap | Not Designated as Hedging Instrument
Total assets and liabilities
Derivative Liability, Notional Amount	1,758.7		1,758.7		913.9
Mortgage Related Derivatives
Financial Assets
Gross Amounts Recognized	0.2		0.2		1.8
Gross Amounts Offset in the Balance Sheet	0		0		0
Net Amounts in the Balance Sheet	0.2		0.2		1.8
Financial Instruments	0		0		0
Fair Value of Financial Collateral in the Balance Sheet	0		0		0
Net Amount	0.2		0.2		1.8
Risk Participation Agreements
Financial Liabilities
Gross Amounts Recognized	0.2		0.2
Gross Amounts Offset in the Balance Sheet	0		0
Net Amounts in the Balance Sheet	0.2		0.2
Financial Instruments	0		0
Fair Value of Financial Collateral in the Balance Sheet	0		0
Net Amount	0.2		0.2
Risk Participation Agreements | Not Designated as Hedging Instrument
Total assets and liabilities
Derivative Liability, Notional Amount	108.5		108.5		$ 0
Repurchase Agreements
Financial Liabilities
Gross Amounts Offset in the Balance Sheet	0		0
Repurchase agreements
Gross Amounts Recognized	1,234.7		1,234.7
Net Amounts in the Balance Sheet	1,234.7		1,234.7
Financial Instruments	0		0
Fair Value of Financial Collateral in the Balance Sheet	1,234.7		1,234.7
Net Amount	$ 0		$ 0

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities - Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivative [Line Items]
Amount of net fee income recognized in other non-interest income
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	0		$ 0
Derivative Instruments and Hedges, Assets	189.5		189.5		$ 695.6
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(10.5)		(10.5)		(4.4)
Financial Instruments	0		0		0
Derivative Asset, Notional Amount	2,021.9		2,021.9		1,691.2
Derivative Asset, Estimated Fair Value	24.8		24.8		28.1
Derivative Liability, Notional Amount	1,867.2		1,867.2		1,103.9
Derivative Liabilities, Estimated Fair Value					18.2
two-year forward starting, three-year pay fixed interest rate swap
Derivative [Line Items]
Derivative Instruments and Hedges, Assets	500		500
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	23.3		23.3
Collateral Pledged
Derivative [Line Items]
Derivative, Fair Value, Net	0		0
Not Designated as Hedging Instrument
Derivative [Line Items]
Amount of net fee income recognized in other non-interest income	1.1	$ 0.1	3.1	$ 1.2
Amount of net gains recognized in mortgage banking revenues	1	0.2	1.5	0.5
Interest Rate Swap
Derivative [Line Items]
Financial Instruments	0		0		0
Derivative Asset, Notional Amount	0		0		87.6
Derivative Asset, Estimated Fair Value	0		0		0.1
Interest Rate Swap | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	200		200		700
Derivative Asset, Estimated Fair Value	10.3		10.3		4.1
Interest Rate Swap | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Asset, Notional Amount	1,758.7		1,758.7		913.9
Derivative Asset, Estimated Fair Value	14.3		14.3		22.2
Derivative Liability, Notional Amount	1,758.7		1,758.7		913.9
Derivative Liabilities, Estimated Fair Value	99.2		99.2		18.1
Risk Participation Agreements
Derivative [Line Items]
Financial Instruments	0		0
Risk Participation Agreements | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liability, Notional Amount	108.5		108.5		0
Derivative Liabilities, Estimated Fair Value	0.2		0.2		0
Forward Contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative, Fair Value, Net	0		0		0
Derivative Asset, Notional Amount	34.6		34.6		0
Derivative Liability, Notional Amount	0		0		102.4
Derivative Liabilities, Estimated Fair Value	0		0		$ 0
Cash Flow Hedging [Member] | Interest Rate Swap | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	$ 0	$ 0	$ 0	$ 0

Capital Stock (Details)

Capital Stock (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Feb. 01, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	May 25, 2022	Dec. 31, 2021	Sep. 12, 2020
Class of Stock [Line Items]
Shares outstanding (in shares)		107,758,038		107,758,038			62,200,456
Common shares issued (in shares)		26,266	18,477	46,913,370	19,081
Stock Repurchase Program, Number of Shares Authorized to be Repurchased								5,000,000
Stock repurchased and retired (in shares)		1,722,044	284	1,759,742	127,464
Stock Repurchased and Retired During Period, Value		$ 64.5	$ 0	$ 65.9	$ 5.4
Shares repurchased, average cost per share (in dollars per share)				$ 37.38
Shares repurchased during the period as percentage of shares authorized for repurchase (percent)				34.40%
Accelerated Share Repurchases, Adjustment to Recorded Amount				$ 64.3
Great Western Bank
Class of Stock [Line Items]
Total consideration exchanged	$ 1,723.3
Class A Common Stock
Class of Stock [Line Items]
Shares outstanding (in shares)							41,699,409
Stock Repurchase Program, Number of Shares Authorized to be Repurchased						5,000,000
Stock repurchased and retired (in shares)		1,720,700
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		3,300,000		3,300,000		1,889,158
Class A Common Stock | Great Western Bank
Class of Stock [Line Items]
Number of shares issued as consideration (in shares)	46,879,601
Class B Common Stock
Class of Stock [Line Items]
Shares outstanding (in shares)							20,501,047
Director [Member]
Class of Stock [Line Items]
Common shares issued (in shares)				33,769	19,081

Earnings per Common Share (Deta

Earnings per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share, Basic and Diluted [Line Items]
Net income	$ 64.1	$ 42.5	$ 30.7	$ 93.9
Weighted average common shares outstanding for basic earnings per share computation (in shares)	109,106,891	61,657,593	101,025,926	61,624,917
Dilutive effects of stock-based compensation (in shares)	24,827	70,228	50,405	98,225
Weighted average common shares outstanding for diluted earnings per common share computation (in shares)	109,131,718	61,727,821	101,076,331	61,723,142
Basic earnings per common share (in dollars per share)	$ 0.59	$ 0.69	$ 0.30	$ 1.52
Diluted earnings per common share (in dollars per share)	$ 0.59	$ 0.69	$ 0.30	$ 1.52
Restricted Stock
Earnings Per Share, Basic and Diluted [Line Items]
Anti-dilutive unvested time restricted stock (in shares)	218,033	84,165	61,058	90,538
Unvested restricted stock
Earnings Per Share, Basic and Diluted [Line Items]
Anti-dilutive unvested time restricted stock (in shares)			500,573	363,960

Regulatory Capital (Details)

Regulatory Capital (Details) $ in Millions	Jan. 01, 2020 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained Earnings (Accumulated Deficit)		$ 993.8	$ 1,052.6
Total risk-based capital:
Actual, Amount		$ 2,908.7	$ 1,659.3
Actual, Ratio		0.1360	0.1411
Minimum Required for Capital Adequacy Purposes, Amount		$ 1,710.7	$ 940.9
Minimum Required for Capital Adequacy Purposes, Ratio		0.0800	0.0800
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 2,245.2	$ 1,235
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		10.50%	10.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 2,138.3	$ 1,176.2
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.1000	0.1000
Banking Regulation, Common Equity Tier One Risk-Based Capital, Capital Adequacy, Minimum		$ 962.2	$ 529.3
Tier 1 risk-based capital:
Actual, Amount		$ 2,451.4	$ 1,469
Actual, Ratio		0.1146	0.1249
Minimum Required for Capital Adequacy Purposes, Amount		$ 1,283	$ 705.7
Minimum Required for Capital Adequacy Purposes, Ratio		0.0600	0.0600
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 1,817.6	$ 999.7
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		8.50%	8.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 1,710.7	$ 940.9
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.0800	0.0800
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum		0.0650	0.0650
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Capital Adequacy, Minimum		0.0450	0.0450
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual		0.1146	0.1177
Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum		$ 1,389.9	$ 764.5
Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual		2,451.4	1,384.8
Common equity tier 1 risk-based capital:
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 1,496.8	$ 823.3
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		7%	7%
Leverage capital ratio:
Actual, Amount		$ 2,451.4	$ 1,469
Actual, Ratio		0.0772	0.0768
Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum		$ 1,269.5	$ 765.5
Capital Adequacy Purposes and Conservation Buffer, Ratio		0.0400	0.0400
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 1,586.8	$ 956.9
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.0500	0.0500
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle	$ 24.1
FIB
Total risk-based capital:
Actual, Amount		$ 2,743.7	$ 1,472.5
Actual, Ratio		0.1287	0.1256
Minimum Required for Capital Adequacy Purposes, Amount		$ 1,705.5	$ 938
Minimum Required for Capital Adequacy Purposes, Ratio		0.0800	0.0800
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 2,238.5	$ 1,231.1
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		10.50%	10.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 2,131.9	$ 1,172.5
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.1000	0.1000
Banking Regulation, Common Equity Tier One Risk-Based Capital, Capital Adequacy, Minimum		$ 959.3	$ 527.6
Tier 1 risk-based capital:
Actual, Amount		$ 2,544	$ 1,382.2
Actual, Ratio		0.1193	0.1179
Minimum Required for Capital Adequacy Purposes, Amount		$ 1,279.1	$ 703.5
Minimum Required for Capital Adequacy Purposes, Ratio		0.0600	0.0600
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 1,812.1	$ 996.6
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		8.50%	8.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 1,705.5	$ 938
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.0800	0.0800
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum		0.0650	0.0650
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Capital Adequacy, Minimum		0.0450	0.0450
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual		0.1193	0.1179
Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum		$ 1,385.7	$ 762.1
Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual		2,544	1,382.2
Common equity tier 1 risk-based capital:
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount		$ 1,492.3	$ 820.8
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio		7%	7%
Leverage capital ratio:
Actual, Amount		$ 2,544	$ 1,382.2
Actual, Ratio		0.0803	0.0724
Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum		$ 1,267	$ 764.1
Capital Adequacy Purposes and Conservation Buffer, Ratio		0.0400	0.0400
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount		$ 1,583.7	$ 955.1
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio		0.0500	0.0500

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Jul. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Shares outstanding (in shares)		107,758,038	62,200,456
Entity Common Stock, Shares Outstanding	106,820,008
Class A Common Stock
Loss Contingencies [Line Items]
Shares outstanding (in shares)			41,699,409
Mortgage Loans Held For Sale [Member]
Loss Contingencies [Line Items]
Mortgage loans with recourse provision in effect		$ 0.7
Construction Contracts
Loss Contingencies [Line Items]
Commitments under construction contracts		$ 3.4

Financial Instruments with Of_2

Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Entity Information [Line Items]
Off-Balance Sheet, Credit Loss, Liability	$ 6.2	$ 3.4	$ 6.2	$ 3.4	$ 6.2	$ 3.8	$ 3.4	$ 3.7
Provision for (reversal of) credit loss expense	1.7	0	(55.6)	4.8
Credit Extension Commitments	4,840.8		4,840.8			2,539.8
Unused Credit Card Lines
Entity Information [Line Items]
Credit Extension Commitments	811.9		811.9			681.6
Standby Letter of Credit
Entity Information [Line Items]
Credit Extension Commitments	91.6		91.6			$ 57.5
Cumulative effect, period of adoption, adjusted balance
Entity Information [Line Items]
Provision for (reversal of) credit loss expense	$ 0	$ 0	$ 2.4	$ (0.3)

Other Comprehensive Income_Lo_3

Other Comprehensive Income/Loss - Schedule of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Investment securities available-for sale:
Change in net unrealized gain during period, pre-tax	$ (161.6)	$ (0.8)	$ (414.2)	$ (67.6)
Change in net unrealized gain during period, tax expense (benefit)	(45.2)	(0.2)	(107.9)	(17.2)
Change in net unrealized gain during period, net of tax	(116.4)	(0.6)	(306.3)	(50.4)
Reclassification adjustment for net gains included in income, pre-tax	0.1	0.1	0.2	0.1
Reclassification adjustment for net gains included in income, tax expense (benefit)	0	0	0	0
Reclassification adjustment for net gains included in income, net of tax	0.1	0.1	0.2	0.1
Amortization of unrealized gains on available-for-sale securities transferred into held-to-maturity, pre-tax	(0.9)	24.8	(23.9)	24.8
Amortization of unrealized gains on available-for-sale securities transferred into held-to-maturity, tax expense (benefit)	(0.2)	6.3	(5.9)	6.3
Amortization of unrealized gains on available-for-sale securities transferred into held-to-maturity, net of tax	(0.7)	18.5	(18)	18.5
Unrealized loss on derivatives, pre-tax	(15)	(0.8)	6.3	(0.9)
Unrealized loss on derivatives, tax expense (benefit)	(4.2)	(0.2)	1.1	(0.2)
Unrealized loss on derivatives, net of tax	(10.8)	(0.6)	5.2	(0.7)
Other comprehensive (loss) income, before tax	(177.4)	23.3	(431.4)	(43.6)
Other Comprehensive Income (Loss), tax expense (benefit)	(49.6)	5.9	(112.6)	(11.1)
Other Comprehensive Income (Loss), Net of Tax	$ (127.8)	$ 17.4	(318.8)	(32.5)
Other than Temporary Impairment Losses, Investments, Reclassification Adjustment of Noncredit Portion from Held-to-maturity to Available-for-sale Securities, before Tax			$ (0.2)	$ 0

Other Comprehensive Income_Lo_4

Other Comprehensive Income/Loss - Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total stockholders’ equity	$ 3,271.9	$ 1,970.9	$ 3,271.9	$ 1,970.9	$ 1,986.6	$ 3,441.1	$ 1,933.4	$ 1,959.8
OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment, after Tax					15
Net unrealized gain (loss) on derivatives	(10.8)	(0.6)	5.2	(0.7)
Other than Temporary Impairment Losses, Investments, Reclassification Adjustment of Noncredit Portion from Held-to-maturity to Available-for-sale Securities, before Tax			0.2	0
Change in net unrealized gain during period, pre-tax	(161.6)	(0.8)	(414.2)	(67.6)
Change in net unrealized gain during period, tax expense (benefit)	(45.2)	(0.2)	(107.9)	(17.2)
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax	(116.4)	(0.6)	(306.3)	(50.4)
Reclassification adjustment for net loss included in income	0.1	0.1	0.2	0.1
Reclassification adjustment for net gains included in income, tax expense (benefit)	0	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.1	0.1	0.2	0.1
Other Comprehensive Loss, Held-to-maturity Security, Reclassification Adjustment from AOCI for Noncredit Portion of OTTI, Sale, Tax			0.1	0
Other Comprehensive Loss, Held-to-maturity Security, Reclassification Adjustment from AOCI for Noncredit Portion of OTTI, Sale, after Tax			0.1	0
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), before Tax	(0.9)	24.8	(23.9)	24.8
Amortization of unrealized gains on available-for-sale securities transferred into held-to-maturity, tax expense (benefit)	(0.2)	6.3	(5.9)	6.3
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax	(0.7)	18.5	(18)	18.5
Unrealized loss on derivatives, pre-tax	(15)	(0.8)	6.3	(0.9)
Unrealized loss on derivatives, tax expense (benefit)	(4.2)	(0.2)	1.1	(0.2)
Other comprehensive (loss) income, before tax	(177.4)	23.3	(431.4)	(43.6)
Other Comprehensive Income (Loss), tax expense (benefit)	(49.6)	5.9	(112.6)	(11.1)
Other Comprehensive Income (Loss), Net of Tax	(127.8)	17.4	(318.8)	(32.5)
Net unrealized loss on investment securities available-for-sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total stockholders’ equity	(333.6)		(333.6)		(29)
OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment, after Tax			(3.9)
Net unrealized gain on derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss) on derivatives			7.7		3
Net accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total stockholders’ equity	$ (329.8)	$ 24.1	$ (329.8)	$ 24.1	$ (11)	$ (202)	$ 6.7	$ 56.6

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring and Non-Recurring Basis (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net	$ 0	$ 0	$ 0	$ 0
Investment debt securities available-for-sale	7,741.1		7,741.1		$ 4,820.5
Derivative assets	24.8		24.8		28.1
Derivative liabilities	99.4		99.4		18.2
Write downs			0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0		0		0
Deferred compensation plan assets	0		0		0
Deferred compensation plan liabilities	0		0		0
Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	127.4		127.4		30.1
Deferred compensation plan assets	19.3		19.3		21.4
Deferred compensation plan liabilities	19.3		19.3		21.4
Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0		0		0
Deferred compensation plan assets	0		0		0
Deferred compensation plan liabilities	0		0		0
U.S. Treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	809.8		809.8		684.7
U.S. Treasury notes | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	809.8		809.8		684.7
U.S. Treasury notes | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
U.S. Treasury notes | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
State, county, and municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	282.2		282.2		427.5
State, county, and municipal securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
State, county, and municipal securities | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	282.2		282.2		427.5
State, county, and municipal securities | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Obligations of U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	225.9		225.9		346.9
Obligations of U.S. government agencies | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Obligations of U.S. government agencies | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	225.9		225.9		346.9
Obligations of U.S. government agencies | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	4,815.4		4,815.4		2,018.1
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	4,815.4		4,815.4		2,018.1
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Private mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	253		253		173.4
Private mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Private mortgage-backed securities | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	253		253		173.4
Private mortgage-backed securities | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	260.8		260.8		270.5
Corporate securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Corporate securities | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	260.8		260.8		270.5
Corporate securities | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Collateral dependent loans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0		0		0
Collateral dependent loans | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0		0		0
Collateral dependent loans | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans					11.7
Collateralized Loan Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	1,094		1,094		899.4
Collateralized Loan Obligations | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Collateralized Loan Obligations | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	1,094		1,094		899.4
Collateralized Loan Obligations | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	7,741.1		7,741.1		4,820.5
Derivative assets	24.8		24.8		28.1
Derivative liabilities	99.4		99.4		18.2
Deferred compensation plan assets	19.3		19.3		21.4
Deferred compensation plan liabilities	19.3		19.3		21.4
Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	127.4		127.4		30.1
Deferred compensation plan assets	19.3		19.3		21.4
Deferred compensation plan liabilities	19.3		19.3		21.4
Estimated Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	809.8		809.8		684.7
Derivative assets	0		0		0
Derivative liabilities	0		0		0
Deferred compensation plan assets	0		0		0
Deferred compensation plan liabilities	0		0		0
Estimated Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	6,931.3		6,931.3		4,135.8
Derivative assets	24.8		24.8		28.1
Derivative liabilities	99.4		99.4		18.2
Deferred compensation plan assets	19.3		19.3		21.4
Deferred compensation plan liabilities	19.3		19.3		21.4
Estimated Fair Value | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	0		0		0
Derivative assets	0		0		0
Derivative liabilities	0		0		0
Deferred compensation plan assets	0		0		0
Deferred compensation plan liabilities	0		0		0
Estimated Fair Value | U.S. Treasury notes | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	809.8		809.8		684.7
Estimated Fair Value | State, county, and municipal securities | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	282.2		282.2		427.5
Estimated Fair Value | Obligations of U.S. government agencies | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	225.9		225.9		346.9
Estimated Fair Value | U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	4,815.4		4,815.4		2,018.1
Estimated Fair Value | Private mortgage-backed securities | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	253		253		173.4
Estimated Fair Value | Corporate securities | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	260.8		260.8		270.5
Estimated Fair Value | Collateral dependent loans | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	85.5		85.5		11.7
Estimated Fair Value | Collateralized Loan Obligations | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	1,094		1,094		899.4
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment debt securities available-for-sale	7,741.1		7,741.1		4,820.5
Derivative assets	24.8		24.8		28.1
Derivative liabilities	99.4		99.4		18.2
Deferred compensation plan assets	19.3		19.3		21.4
Deferred compensation plan liabilities	19.3		19.3		21.4
Carrying Amount | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	85.5		85.5		11.7
Long-lived assets to be disposed of by sale	7.1		7.1		1.3
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	24.6		24.6		26.3
Derivative liabilities	99.2		99.2		18.2
Interest Rate Swap | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0		0
Derivative liabilities	0		0		0
Interest Rate Swap | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	24.6		24.6		26.3
Derivative liabilities	99.2		99.2		18.2
Interest Rate Swap | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0		0
Derivative liabilities	0		0		0
Interest Rate Swap | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	24.6		24.6		26.3
Derivative liabilities	99.2		99.2		18.2
Interest Rate Lock Commitments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0		0
Interest Rate Lock Commitments | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0.2		0.2		1.8
Interest Rate Lock Commitments | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0		0
Interest Rate Lock Commitments | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0.2		0.2		1.8
Risk Participation Agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.2		0.2
Risk Participation Agreements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0		0
Risk Participation Agreements | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.2		0.2
Risk Participation Agreements | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0		0
Risk Participation Agreements | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.2		0.2
Long-lived assets to be disposed of by sale | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets to be disposed of by sale	0		0		0
Long-lived assets to be disposed of by sale | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets to be disposed of by sale	0		0		0
Long-lived assets to be disposed of by sale | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets to be disposed of by sale	7.1		7.1		1.3
Long-lived assets to be disposed of by sale | Estimated Fair Value | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets to be disposed of by sale	$ 7.1		$ 7.1		$ 1.3

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Inputs, Quantitative Information (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Material write downs	$ 0
Significant Unobservable Inputs (Level 3) | Carrying Amount | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Collateral dependent loans	85.5	$ 11.7
Collateral dependent loans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Collateral dependent loans	0	0
Collateral dependent loans | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Collateral dependent loans	0	0
Collateral dependent loans | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Collateral dependent loans		11.7
Collateral dependent loans | Significant Unobservable Inputs (Level 3) | Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Collateral dependent loans	$ 85.5	11.7
Collateral dependent loans | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0.01
Collateral dependent loans | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0.18
Collateral dependent loans | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	(0.07)
Other real estate owned | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other real estate owned	$ 0	0
Other real estate owned | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other real estate owned	0	0
Other real estate owned | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other real estate owned	16.8	2
Other real estate owned | Significant Unobservable Inputs (Level 3) | Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other real estate owned	$ 16.8	2
Other real estate owned | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0
Other real estate owned | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0
Other real estate owned | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0
Long-lived assets to be disposed of by sale | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Long-lived assets to be disposed of by sale	$ 0	0
Long-lived assets to be disposed of by sale | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Long-lived assets to be disposed of by sale	0	0
Long-lived assets to be disposed of by sale | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Long-lived assets to be disposed of by sale	7.1	1.3
Long-lived assets to be disposed of by sale | Significant Unobservable Inputs (Level 3) | Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Long-lived assets to be disposed of by sale	$ 7.1	$ 1.3
Long-lived assets to be disposed of by sale | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0
Long-lived assets to be disposed of by sale | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0
Long-lived assets to be disposed of by sale | Discount Rate | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount rate	0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Instruments by Level of Valuation Inputs (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financial assets:
Securities Purchased under Agreements to Resell	$ 202.2	$ 0
Investment debt securities available-for-sale	7,741.1	4,820.5
Investment debt securities held-to-maturity	2,860.5	1,667.5
Derivative assets	24.8	28.1
Financial liabilities:
Derivative liabilities	99.4	18.2
Carrying Amount
Financial assets:
Cash and cash equivalents	1,059.3	2,344.8
Securities Purchased under Agreements to Resell	202.2
Investment debt securities available-for-sale	7,741.1	4,820.5
Investment debt securities held-to-maturity	3,130	1,687.6
Accrued interest receivable	90.6	47.4
Mortgage servicing rights, net	32.1	28.2
Loans held for sale	127.4	30.1
Net loans held for investment	16,942.1	9,209.4
Derivative assets	24.8	28.1
Deferred compensation plan assets	19.3	21.4
Total financial assets	29,368.9	18,217.5
Financial liabilities:
Total deposits, excluding time deposits	25,368.1	15,303.1
Time deposits	1,495.7	966.5
Securities sold under repurchase agreements	1,234.7	1,051.1
Accrued interest payable	4.3	3.7
Long-term debt	120.4	112.4
Subordinated debentures held by subsidiary trusts	163.1	87
Derivative liabilities	99.4	18.2
Deferred compensation plan liabilities	19.3	21.4
Total financial liabilities	28,505	17,563.4
Estimated Fair Value
Financial assets:
Cash and cash equivalents	1,059.3	2,344.8
Securities Purchased under Agreements to Resell	202.2
Investment debt securities available-for-sale	7,741.1	4,820.5
Investment debt securities held-to-maturity	2,860.5	1,667.5
Accrued interest receivable	90.6	47.4
Mortgage servicing rights, net	37	28.2
Loans held for sale	127.4	30.1
Net loans held for investment	16,874	9,254.3
Derivative assets	24.8	28.1
Deferred compensation plan assets	19.3	21.4
Total financial assets	29,036.2	18,242.3
Financial liabilities:
Total deposits, excluding time deposits	25,368.1	15,303.1
Time deposits	1,467.2	963.1
Securities sold under repurchase agreements	1,234.7	1,051.1
Accrued interest payable	4.3	3.7
Long-term debt	119.3	120.7
Subordinated debentures held by subsidiary trusts	157.5	85.5
Derivative liabilities	99.4	18.2
Deferred compensation plan liabilities	19.3	21.4
Total financial liabilities	28,469.8	17,566.8
Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	1,059.3	2,344.8
Securities Purchased under Agreements to Resell	0
Investment debt securities available-for-sale	809.8	684.7
Investment debt securities held-to-maturity	293.1	0
Accrued interest receivable	0	0
Mortgage servicing rights, net	0	0
Loans held for sale	0	0
Net loans held for investment	0	0
Derivative assets	0	0
Deferred compensation plan assets	0	0
Total financial assets	2,162.2	3,029.5
Financial liabilities:
Total deposits, excluding time deposits	25,368.1	15,303.1
Time deposits	0	0
Securities sold under repurchase agreements	0	0
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Derivative liabilities	0	0
Deferred compensation plan liabilities	0	0
Total financial liabilities	25,368.1	15,303.1
Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Securities Purchased under Agreements to Resell	202.2
Investment debt securities available-for-sale	6,931.3	4,135.8
Investment debt securities held-to-maturity	2,567.4	1,667.5
Accrued interest receivable	90.6	47.4
Mortgage servicing rights, net	37	28.2
Loans held for sale	127.4	30.1
Net loans held for investment	16,788.5	9,242.6
Derivative assets	24.8	28.1
Deferred compensation plan assets	19.3	21.4
Total financial assets	26,788.5	15,201.1
Financial liabilities:
Total deposits, excluding time deposits	0	0
Time deposits	1,467.2	963.1
Securities sold under repurchase agreements	1,234.7	1,051.1
Accrued interest payable	4.3	3.7
Long-term debt	119.3	120.7
Subordinated debentures held by subsidiary trusts	157.5	85.5
Derivative liabilities	99.4	18.2
Deferred compensation plan liabilities	19.3	21.4
Total financial liabilities	3,101.7	2,263.7
Significant Unobservable Inputs (Level 3) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Securities Purchased under Agreements to Resell	0
Investment debt securities available-for-sale	0	0
Investment debt securities held-to-maturity	0	0
Accrued interest receivable	0	0
Mortgage servicing rights, net	0	0
Loans held for sale	0	0
Net loans held for investment	85.5	11.7
Derivative assets	0	0
Deferred compensation plan assets	0	0
Total financial assets	85.5	11.7
Financial liabilities:
Total deposits, excluding time deposits	0	0
Time deposits	0	0
Securities sold under repurchase agreements	0	0
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Derivative liabilities	0	0
Deferred compensation plan liabilities	0	0
Total financial liabilities	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details)	Jul. 25, 2022 $ / shares
Class A Common Stock | Subsequent Event
Subsequent Event [Line Items]
Dividend amount per share (in dollars)	$ 0.41