Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cash and cash equivalents:
Cash and due from banks	$ 552,900	$ 548,387
Federal funds sold and interest-earning deposits with banks	694,581	580,491
Deposits in other financial institutions (restricted cash)	266,268	183,685
Total cash and cash equivalents	1,513,749	1,312,563
Trading securities, at fair value	56,580	31,263
Investment securities:
Securities held to maturity (fair value of $2,144,514 and $2,250,168)	2,585,155	2,683,241
Securities available for sale, at fair value	4,949,334	5,326,822
Other investments	196,728	179,717
Total investment securities	7,731,217	8,189,780
Loans held for sale	42,951	28,968
Loans:
Total loans	31,536,785	30,177,862
Less allowance for credit losses	(427,392)	(356,444)
Loans, net	31,109,393	29,821,418
Other real estate owned	1,080	1,023
Bank property held for sale	13,472	17,754
Premises and equipment, net	518,353	520,635
Bank owned life insurance ("BOLI")	979,494	964,708
Deferred tax assets	164,426	177,801
Derivatives assets	174,480	211,016
Mortgage servicing rights	87,539	86,610
Core deposit and other intangibles	102,256	116,450
Goodwill	1,923,106	1,923,106
Other assets	522,236	515,601
Total assets	44,940,332	43,918,696
Deposits:
Noninterest-bearing	11,489,483	13,168,656
Interest-bearing	25,252,395	23,181,967
Total deposits	36,741,878	36,350,623
Federal funds purchased	246,910	213,597
Securities sold under agreements to repurchase	334,536	342,820
Corporate and subordinated debentures	392,090	392,275
Other borrowings	400,000
Reserve for unfunded commitments	63,399	67,215
Derivative liabilities	975,717	1,034,143
Other liabilities	495,792	443,096
Total liabilities	39,650,322	38,843,769
Shareholders' equity:
Common stock - $2.50 par value; authorized 160,000,000 shares; 75,995,979 and 75,704,563 shares issued and outstanding, respectively	189,990	189,261
Surplus	4,228,910	4,215,712
Retained earnings	1,533,508	1,347,042
Accumulated other comprehensive loss	(662,398)	(677,088)
Total shareholders' equity	5,290,010	5,074,927
Total liabilities and shareholders' equity	44,940,332	43,918,696
Acquired - non-purchased credit deteriorated loans
Loans:
Total loans	5,275,913	5,943,092
Acquired - purchased credit deteriorated loans
Loans:
Total loans	1,269,983	1,429,731
Non-acquired loans
Loans:
Total loans	$ 24,990,889	$ 22,805,039