CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Statement of Cash Flows [Abstract]
Net income	$ 89,476	$ 90,822
Adjustments to reconcile net income to net cash provided by operating activities:
Provision (recovery of provision) for credit losses	7,903	(3,186)
Depreciation of premises and equipment	3,452	3,891
Depreciation of equipment owned and leased to others	7,912	10,562
Stock-based compensation	2,510	2,962
Amortization of investment securities premiums and accretion of discounts, net	3,098	5,024
Amortization of mortgage servicing rights	1,033	1,663
Mortgage servicing rights impairment recoveries	0	(812)
Amortization of right of use assets	2,369	2,317
Deferred income taxes	(5,428)	13,087
Losses on investment securities available-for-sale	0	680
Originations of loans held for sale, net of principal collected	(73,718)	(210,256)
Proceeds from the sales of loans held for sale	85,206	194,753
Net gain on sale of loans held for sale	(1,262)	(6,206)
Net gain on sale of other real estate and repossessions	(267)	(636)
Change in interest receivable	(2,866)	1,687
Change in interest payable	1,249	(1,572)
Change in other assets	10,049	11,900
Change in other liabilities	3,650	(11,829)
Other	(2,623)	223
Net Cash Provided by (Used in) Operating Activities	131,743	105,074
Investing activities:
Proceeds from sales of investment securities available-for-sale	0	99,208
Proceeds from maturities and paydowns of investment securities available-for-sale	162,766	256,538
Purchases of investment securities available-for-sale	(304,078)	(768,238)
Net change in partnership investments	(16,917)	(15,146)
Net change in other investments	1,651	240
Loans sold or participated to others	35,252	25,970
Proceeds from principal payments on direct finance leases	48,610	27,072
Net change in loans and leases	(500,707)	72,195
Net change in equipment owned under operating leases	7,557	3,000
Purchases of premises and equipment	(1,269)	(1,389)
Proceeds from disposal of premises and equipment	18	125
Purchases of bank owned life insurance policies	(10,000)	0
Proceeds from sales of other real estate and repossessions	2,421	3,527
Net Cash Provided by (Used in) Investing Activities	(574,696)	(296,898)
Financing activities:
Net change in demand deposits and savings accounts	47,392	806,318
Net change in time deposits	(105,226)	(229,841)
Net change in short-term borrowings	140,435	65,024
Payments on long-term debt	(23,740)	(3,288)
Stock issued under stock purchase plans	252	90
Acquisition of treasury stock	(6,836)	(30,067)
Net contributions from (distributions to) noncontrolling interests	7,057	1,228
Cash dividends paid on common stock	(23,964)	(23,405)
Net change in financing activities	35,370	586,059
Net change in cash and cash equivalents	(407,583)	394,235
Cash and cash equivalents, beginning of year	525,187	243,047
Cash and cash equivalents, end of period	117,604	637,282
Non-cash transactions:
Loans transferred to other real estate and repossessed assets	1,322	1,554
Common stock matching contribution to Employee Stock Ownership and Profit Sharing Plan	683	715
Right of use assets obtained in exchange for lease obligations	$ 846	$ 698