Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest Income:
Interest and fees on loans and leases	$ 762,713	$ 789,719	$ 924,693
Taxable interest and dividends on securities	159,001	189,683	207,294
Non-taxable interest on securities	20,884	21,878	21,869
Loans held for sale	246	769	727
Interest income	942,844	1,002,049	1,154,583
Interest Expense:
Deposits	20,131	67,897	129,577
Securities sold under agreements to repurchase and other borrowings	3,040	5,941	17,953
Federal Home Loan Bank advances	1,708	18,767	31,399
Long-term debt	16,876	18,051	20,527
Interest expense	41,755	110,656	199,456
Net interest income	901,089	891,393	955,127
(Benefit) provision for credit losses	(54,500)	137,750	37,800
Net interest income (loss) after provision for loan and lease losses	955,589	753,643	917,327
Non-interest Income:
Deposit service fees	162,710	156,032	168,022
Loan and lease related fees	36,658	29,127	31,327
Wealth and investment services	39,586	32,916	32,932
Mortgage banking activities	6,219	18,295	6,115
Increase in cash surrender value of life insurance policies	14,429	14,561	14,612
Net (gain) on sale of investment securities	0	8	29
Other income	63,770	34,338	32,278
Total non-interest income	323,372	285,277	285,315
Non-interest Expense:
Compensation and benefits	419,989	428,391	395,402
Occupancy	55,346	71,029	57,181
Technology and equipment	112,831	112,273	105,283
Intangible assets amortization	4,513	4,160	3,847
Marketing	12,051	14,125	16,286
Professional and outside services	47,235	32,424	21,380
Deposit insurance	15,794	18,316	17,954
Other expense	77,341	78,228	98,617
Total non-interest expense	745,100	758,946	715,950
Income before income tax expense	533,861	279,974	486,692
Income tax expense	124,997	59,353	103,969
Net income	408,864	220,621	382,723
Preferred stock dividends	(7,875)	(7,875)	(7,875)
Net income available to common shareholders, basic	400,989	212,746	374,848
Net income available to common shareholders, diluted	$ 400,989	$ 212,746	$ 374,848
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 4.43	$ 2.35	$ 4.07
Earnings per common share, Diluted (in dollars per share)	$ 4.42	$ 2.35	$ 4.06