Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Cash and due from banks	$ 274,057	$ 280,518
Interest-bearing deposits with banks	3,836,809	1,336,394
Debt securities held for investment (fair value: $2,984 and $2,984, respectively)	2,982	2,964
Debt securities available for sale at fair value	526,502	552,232
Loans held for sale	20,950	53,719
Loans held for investment (net of unearned interest)	6,016,936	6,394,506
Allowance for credit losses	(86,463)	(91,366)
Loans, net of allowance for credit losses	5,930,473	6,303,140
Premises and equipment, net	268,160	261,677
Other real estate owned	38,932	32,179
Intangible assets, net	18,325	18,999
Goodwill	149,922	149,922
Accrued interest receivable and other assets	235,659	220,613
Total assets	11,302,771	9,212,357
Deposits:
Noninterest-bearing	4,594,324	3,790,900
Interest-bearing	5,397,720	4,273,804
Total deposits	9,992,044	8,064,704
Short-term borrowings	3,500	1,100
Accrued interest payable and other liabilities	74,380	51,864
Subordinated debt	85,973	26,804
Total liabilities	10,155,897	8,144,472
Stockholders' equity:
Common stock, $1.00 par, 40,000,000 shares authorized; shares issued and outstanding: 32,572,217 and 32,719,852, respectively	32,572	32,720
Capital surplus	158,877	156,574
Retained earnings	950,560	871,161
Accumulated other comprehensive income, net of income tax of $1,533 and $2,513, respectively	4,865	7,430
Total stockholders' equity	1,146,874	1,067,885
Total liabilities and stockholders' equity	11,302,771	9,212,357
Senior Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value
Cumulative Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value