CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net income	$ 158,215	$ 107,498
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(10,395)	59,051
Depreciation and amortization	24,307	24,955
Stock-based compensation expense	7,568	5,749
Pension expense (income)	2,530	1,705
Net amortization (accretion) on investment securities	23,828	13,570
Net (gain) loss on sales of investment securities	745	55
Unrealized gain (loss) on equity securities	(381)	(70)
Originations of loans held for sale	(618,904)	(691,716)
Net gains from sales of loans held for sale	(26,529)	(38,087)
Proceeds from sales of loans held for sale	644,405	674,475
Deferred income taxes	7,238	(9,744)
Amortization of operating leases	5,532	5,973
Payments for operating leases	(5,203)	(5,801)
Decrease (increase) cash surrender value of life insurance	381	985
Decrease (increase) in interest receivable	4,833	(13,262)
(Decrease) increase in interest payable	(1,432)	(4,559)
Decrease (increase) in other assets	93,701	(349,951)
(Decrease) increase in other liabilities	(25,633)	177,275
Net cash provided by (used in) operating activities	284,044	(43,869)
Proceeds from Sale of Debt Securities, Available-for-sale	361,736	42,628
Investing activities
Proceeds from calls, paydowns and maturities of securities available-for-sale	850,248	658,521
Payments to Acquire Debt Securities, Available-for-sale	1,923,277	787,048
Proceeds from calls, paydowns and maturities of securities held-to-maturity	29,036	25,005
Payments to Acquire Held-to-maturity Securities	(1,000)	0
Payments to Acquire Other Investments	6,655	18,659
Proceeds from Maturities, Prepayments and Calls of Other Investments	42,403	0
Net decrease (increase) in interest-bearing deposits with other banks	(9,494)	18,142
Net decrease (increase) in loans and leases	530,960	(1,007,585)
Proceeds from disposal of other real estate owned	1,036	1,487
Purchases of premises and equipment	(10,603)	(13,404)
Net cash provided by (used in) investing activities	(135,610)	(1,080,913)
Financing activities
Net (decrease) increase in total deposits	445,378	1,357,201
Net (decrease) increase in short-term borrowings	22,256	(1,068,523)
Payments of long-term debt	463,382	105,201
Proceeds from (Repayments of) Other Long-term Debt	0	881,673
Proceeds from Issuance of Subordinated Long-term Debt	0	150,000
Cash dividends paid on common stock	(65,949)	(67,317)
Treasury stock purchase	108,077	16,686
Proceeds from exercise of stock options	34	72
Net cash provided by (used in) financing activities	(169,740)	1,131,219
Cash and due from banks:
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(21,306)	6,437
Cash and due from banks at beginning of period	231,054	200,691
Cash and due from banks at end of period	209,748	207,128
Supplemental schedule for investing activities
Interest Paid, Excluding Capitalized Interest, Operating Activities	25,465	61,456
Income Taxes Paid	$ 16,448	$ 26,626