Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 244,100	$ 196,500
Interest bearing deposits in banks	577,800	562,300
Federal funds sold	100	100
Total cash and cash equivalents	822,000	758,900
Investment securities:
Available-for-sale	2,270,700	2,208,700
Held-to-maturity (estimated fair values of $400.7 and $483.3 at December 31, 2018 and 2017, respectively)	406,800	484,500
Total investment securities	2,677,500	2,693,200
Loans held for investment	8,470,400	7,567,700
Mortgage loans held for sale	33,300	46,600
Total loans	8,503,700	7,614,300
Less allowance for loan losses	73,000	72,100
Net loans	8,430,700	7,542,200
Goodwill	546,700	444,700
Goodwill	245,200	241,900
Indefinite-lived Intangible Assets (Excluding Goodwill)	56,900	49,100
Premises and equipment, net of accumulated depreciation	275,100	260,600
Core deposit intangibles, net of accumulated amortization	14,400	10,100
Accrued interest receivable	44,900	38,000
Mortgage servicing rights, net of accumulated amortization and impairment reserve	27,700	24,800
Other real estate owned (“OREO”)	0	4,000
Other assets	159,100	145,800
Total assets	13,300,200	12,213,300
Deposits:
Non-interest bearing	3,158,300	2,900,000
Interest bearing	7,522,400	7,034,900
Total deposits	10,680,700	9,934,900
Securities sold under repurchase agreements	712,400	643,000
Accounts payable and accrued expenses	94,100	86,600
Accrued interest payable	7,800	5,600
Deferred tax liability, net	8,600	0
Long-term debt	15,800	13,100
Other borrowed funds	0	20,000
Subordinated debentures held by subsidiary trusts	86,900	82,500
Total liabilities	11,606,300	10,785,700
Stockholders’ equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued or outstanding as of December 31, 2018 and 2017	0	0
Common stock	866,700	687,000
Retained earnings	851,800	752,600
Accumulated other comprehensive income (loss), net	(24,600)	(12,000)
Total stockholders’ equity	1,693,900	1,427,600
Total liabilities and stockholders’ equity	$ 13,300,200	$ 12,213,300