CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Cash Flows [Abstract]
Net income	$ 118,557	$ 81,461	$ 92,015
Adjustments to reconcile net income to net cash provided by operating activities:
(Recovery of) provision for credit losses	(4,303)	36,001	15,833	[1]
Depreciation of premises and equipment	5,093	5,673	5,786
Depreciation - leased equipment	13,694	20,203	25,128
Stock-based compensation	4,214	3,293	2,765
Amortization of investment securities premiums and accretion of discounts, net	6,684	6,057	4,014
Amortization of mortgage servicing rights	2,117	2,361	1,312
Mortgage servicing rights (recoveries) impairments	(812)	812	0
Amortization of right of use assets	3,095	2,842	3,046
Deferred income taxes	15,396	(24,160)	(5,730)
Losses (gains) on investment securities available-for-sale	680	(279)	0
Originations of loans held for sale, net of principal collected	(261,559)	(330,990)	(145,097)
Proceeds from the sales of loans held for sale	267,694	351,337	139,050
Net gains on sale of loans held for sale	(6,534)	(12,955)	(2,940)
Net gains on sale of other real estate and repossessions	(672)	(138)	(487)
Net gain on sale of premises and equipment	0	0	(1,251)
Change in interest receivable	2,482	(1,117)	(245)
Change in interest payable	(2,111)	(9,923)	4,968
Change in other assets	17,757	12,782	11,213
Change in other liabilities	(14,990)	10,293	13,492
Other	279	940	1,734
Net change in operating activities	166,761	154,493	164,606
Investing activities:
Proceeds from sales of investment securities available-for-sale	99,208	8,403	0
Proceeds from maturities and paydowns of investment securities available-for-sale	336,364	443,617	317,295
Purchases of investment securities available-for-sale	(1,145,697)	(597,296)	(351,189)
Net change in partnership investments	(24,897)	(54,981)	(33,840)
Net change in other investments	240	985	(10)
Loans sold or participated to others	54,623	17,462	53,369
Proceeds from principal payments on direct finance leases	40,751	54,771	69,188
Net change in loans and leases	36,414	(489,477)	(392,475)
Net change in equipment owned under operating leases	2,913	26,414	(2,495)
Purchases of premises and equipment	(2,886)	(2,850)	(8,033)
Proceeds from disposal of premises and equipment	129	23	3,418
Proceeds from sales of other real estate and repossessions	4,279	10,271	10,855
Net change in investing activities	(598,559)	(582,658)	(333,917)
Financing activities:
Net change in demand deposits and savings accounts	1,016,257	1,069,843	54,272
Net change in time deposits	(283,220)	(481,141)	180,732
Net change in short-term borrowings	49,386	4,748	(53,451)
Proceeds from issuance of long-term debt	0	10,000	0
Payments on long-term debt	(13,460)	(2,905)	(2,695)
Stock issued under stock purchase plans	90	39	49
Acquisition of treasury stock	(33,136)	(6,415)	(15,085)
Net change in noncontrolling interests	9,361	23,442	18,796
Cash dividends paid on common stock	(31,340)	(29,764)	(29,021)
Net change in financing activities	713,938	587,847	153,597
Net change in cash and cash equivalents	282,140	159,682	(15,714)
Cash and cash equivalents, beginning of year	243,047	83,365	99,079
Cash and cash equivalents, end of year	$ 525,187	$ 243,047	$ 83,365

[1] ASU 2016-13 adopted during 2020 therefore 2019 provision amount reflects the incurred method.