Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 261,400	$ 241,500
Federal funds sold	2,015,300	835,200
Interest bearing deposits in banks	100	100
Total cash and cash equivalents	2,276,800	1,076,800
Investment securities:
Available-for-sale	4,008,700	2,960,000
Held-to-maturity (estimated fair values of $94.5 and $400.7 at December 31, 2019 and 2018, respectively)	51,600	92,300
Total investment securities	4,060,300	3,052,300
Mortgage loans held for sale, at fair value	74,000	100,900
Loans and Leases Receivable, Allowance	9,807,500	8,930,700
Less allowance for loan losses	144,300	73,000
Net loans	9,663,200	8,857,700
Goodwill	621,600	621,600
Company-owned life insurance	296,400	293,800
Premises and equipment, net of accumulated depreciation	312,300	306,000
Core deposit intangibles, net of accumulated amortization	51,200	62,100
Accrued interest receivable	51,100	46,700
Mortgage servicing rights, net of accumulated amortization and impairment reserve	24,000	30,200
Other real estate owned (“OREO”)	2,500	8,500
Other assets	215,300	187,600
Total assets	17,648,700	14,644,200
Deposits:
Non-interest bearing	4,633,500	3,426,500
Interest bearing	9,583,500	8,237,000
Total deposits	14,217,000	11,663,500
Securities sold under repurchase agreements	1,091,400	697,600
Accounts payable and accrued expenses	144,400	129,600
Accrued interest payable	5,800	12,100
Deferred tax liability, net	27,200	26,700
Long-term debt	112,400	13,900
Allowance for credit losses on off-balance sheet credit exposures	3,700	0
Subordinated debentures held by subsidiary trusts	87,000	86,900
Total liabilities	$ 15,688,900	12,630,300
Preferred Stock, Shares Authorized	100,000
Stockholders’ equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued or outstanding as of December 31, 2019 and 2018	$ 0	0
Common stock	941,100	1,049,300
Retained earnings	962,100	953,600
Accumulated other comprehensive income (loss), net	56,600	11,000
Total stockholders’ equity	1,959,800	2,013,900
Total liabilities and stockholders’ equity	$ 17,648,700	$ 14,644,200