CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Statement of Cash Flows [Abstract]
Net income	$ 56,731	$ 58,341
Adjustments to reconcile net income to net cash provided by operating activities:
Provision (recovery of provision) for credit losses	4,736	(627)
Depreciation of premises and equipment	2,322	2,675
Depreciation of equipment owned and leased to others	5,679	7,323
Stock-based compensation	1,619	1,726
Amortization of investment securities premiums and accretion of discounts, net	2,110	3,372
Amortization of mortgage servicing rights	736	1,109
Mortgage servicing rights impairment recoveries	0	(589)
Amortization of right of use assets	1,577	1,545
Deferred income taxes	(3,259)	8,343
Losses on investment securities available-for-sale	0	680
Originations of loans held for sale, net of principal collected	(55,752)	(135,647)
Proceeds from the sales of loans held for sale	64,533	146,251
Net gain on sale of loans held for sale	(1,022)	(4,172)
Net gain on sale of other real estate and repossessions	(269)	(303)
Purchases of bank owned life insurance policies	(10,000)	0
Change in interest receivable	(377)	1,104
Change in interest payable	409	(1,224)
Change in other assets	(729)	3,113
Change in other liabilities	9,788	(6,697)
Other	(1,879)	233
Net Cash Provided by (Used in) Operating Activities	76,953	86,556
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	102,979	182,499
Purchases of investment securities available-for-sale	(206,223)	(515,496)
Net change in partnership investments	(10,081)	(13,756)
Net change in other investments	1,651	0
Loans sold or participated to others	10,223	15,903
Proceeds from principal payments on direct finance leases	21,358	20,086
Net change in loans and leases	(237,225)	(34,519)
Net change in equipment owned under operating leases	6,175	1,706
Purchases of premises and equipment	(552)	(947)
Proceeds from disposal of premises and equipment	18	28
Proceeds from sales of other real estate and repossessions	2,305	2,240
Net Cash Provided by (Used in) Investing Activities	(309,372)	(243,048)
Financing activities:
Net change in demand deposits and savings accounts	165,019	574,114
Net change in time deposits	(99,188)	(174,732)
Net change in short-term borrowings	(32,188)	21,703
Payments on long-term debt	(23,414)	(2,870)
Stock issued under stock purchase plans	252	90
Acquisition of treasury stock	(6,836)	(20,398)
Net contributions from (distributions to) noncontrolling interests	1,180	393
Cash dividends paid on common stock	(15,830)	(15,408)
Net change in financing activities	(11,005)	382,892
Net change in cash and cash equivalents	(243,424)	226,400
Cash and cash equivalents, beginning of year	525,187	243,047
Cash and cash equivalents, end of period	281,763	469,447
Non-cash transactions:
Loans transferred to other real estate and repossessed assets	1,279	1,120
Common stock matching contribution to Employee Stock Ownership and Profit Sharing Plan	683	715
Right of use assets obtained in exchange for lease obligations	$ 561	$ 615