Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 254.0	$ 261.4
Interest bearing deposits in banks	1,941.9	2,015.3
Federal funds sold	0.1	0.1
Total cash and cash equivalents	2,196.0	2,276.8
Investment securities:
Available-for-sale	4,020.1	4,008.7
Held-to-maturity, net (estimated fair values of $855.6 and $55.0 at March 31, 2021 and December 31, 2020, respectively)	866.3	51.6
Total investment securities	4,886.4	4,060.3
Mortgage loans held for sale, at fair value	57.2	74.0
Loans held for investment, net of deferred fees and costs	9,863.2	9,807.5
Allowance for credit losses	136.6	144.3
Net loans held for investment	9,726.6	9,663.2
Goodwill	621.6	621.6
Company-owned life insurance	297.6	296.4
Premises and equipment, net of accumulated depreciation	305.5	312.3
Core deposit intangibles, net of accumulated amortization	48.6	51.2
Accrued interest receivable	50.0	51.1
Mortgage servicing rights, net of accumulated amortization and impairment reserve	28.0	24.0
Other real estate owned (“OREO”)	2.2	2.5
Other assets	223.7	215.3
Total assets	18,443.4	17,648.7
Deposits:
Non-interest bearing	5,004.0	4,633.5
Interest bearing	10,090.0	9,583.5
Total deposits	15,094.0	14,217.0
Securities sold under repurchase agreements	1,052.6	1,091.4
Accounts payable and accrued expenses	133.8	144.4
Accrued interest payable	6.9	5.8
Deferred tax liability, net	19.9	27.2
Long-term debt	112.4	112.4
Allowance for credit losses on off-balance sheet credit exposures	3.4	3.7
Subordinated debentures held by subsidiary trusts	87.0	87.0
Total liabilities	16,510.0	15,688.9
Stockholders’ equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued and outstanding as of March 31, 2021 or December 31, 2020	0.0	0.0
Common stock	938.5	941.1
Retained earnings	988.2	962.1
Accumulated other comprehensive income, net	6.7	56.6
Total stockholders’ equity	1,933.4	1,959.8
Total liabilities and stockholders’ equity	$ 18,443.4	$ 17,648.7
Preferred Stock, Shares Authorized	100,000	100,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0