CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets [Abstract]
Cash and noninterest-bearing due from banks	$ 209,255	$ 268,649
Restricted cash	13,049	31,447
Interest-bearing due from banks	2,597,172	877,286
Federal funds sold and other	0	0
Cash and cash equivalents	2,819,476	1,177,382
Securities purchased with agreement to resell	509,872	513,276
Debt Securities, Available-for-sale	3,825,203	3,558,870
Securities held-to-maturity (fair value of $2.8 billion and $2.7 billion, net of allowance for credit losses of $1.9 million and $1.6 million at March 31, 2023 and Dec. 31, 2022, respectively)	3,053,628	3,079,050
Consumer loans held-for-sale	58,758	42,237
Commercial loans held-for-sale	23,087	21,093
Loans	30,297,871	29,041,605
Less allowance for credit losses	(313,841)	(300,665)
Loans, net	29,984,030	28,740,940
Premises and equipment, net	354,713	327,885
Equity method investment	438,303	443,185
Accrued interest receivable	143,965	161,182
Goodwill	1,846,973	1,846,973
Core deposits and other intangible assets	32,761	34,555
Other real estate owned	7,802	7,952
Other assets	2,021,016	2,015,441
Total assets	45,119,587	41,970,021
Deposits:
Noninterest-bearing	9,018,439	9,812,744
Interest-bearing	8,944,353	7,884,605
Savings and money market accounts	14,136,850	13,774,534
Time	4,078,911	3,489,355
Total deposits	36,178,553	34,961,238
Securities sold under agreements to repurchase	149,777	194,910
Federal Home Loan Bank advances	2,166,508	464,436
Subordinated debt and other borrowings	424,276	424,055
Accrued interest payable	31,728	19,478
Other liabilities	484,617	386,512
Total liabilities	39,435,459	36,450,629
Shareholders' equity:
Preferred stock, no par value, 10.0 million shares authorized; 225,000 shares non-cumulative perpetual preferred stock, Series B, liquidation preference $225.0 million, issued and outstanding at March 31, 2023 and Dec. 31, 2022, respectively	217,126	217,126
Common stock, par value $1.00; 180.0 million shares authorized; 76.7 million and 76.5 million shares issued and outstanding at March 31, 2023 and Dec. 31, 2022, respectively	76,739	76,454
Additional paid-in capital	3,079,020	3,074,867
Retained earnings	2,458,006	2,341,706
Accumulated other comprehensive loss, net of taxes	(146,763)	(190,761)
Total shareholders' equity	5,684,128	5,519,392
Liabilities and Equity	$ 45,119,587	$ 41,970,021