CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement of Cash Flows [Abstract]
Net income	$ 90,822	$ 54,998
Adjustments to reconcile net income to net cash provided by operating activities:
(Recovery of) provision for credit losses*	(3,186)	31,031	[1]
Depreciation of premises and equipment	3,891	4,255
Depreciation of equipment owned and leased to others	10,562	15,263
Stock-based compensation	2,962	2,377
Amortization of investment securities premiums and accretion of discounts, net	5,024	4,238
Amortization of mortgage servicing rights	1,663	1,757
Mortgage servicing rights impairment (recoveries) charges	(812)	808
Amortization of right of use assets	3,406	2,115
Deferred income taxes	13,087	(10,509)
Losses (gains) on investment securities available-for-sale	680	(279)
Originations of loans held for sale, net of principal collected	(210,258)	(248,639)
Proceeds from the sales of loans held for sale	194,549	258,253
Net gain on sale of loans held for sale	(6,000)	(10,327)
Net gain on sale of other real estate and repossessions	(636)	(73)
Change in interest receivable	1,687	(2,440)
Change in interest payable	(1,572)	(6,271)
Change in other assets	10,811	2,312
Change in other liabilities	(11,829)	(2,906)
Other	223	1,049
Net Cash Provided by (Used in) Operating Activities	105,074	97,012
Investing activities:
Proceeds from sales of investment securities available-for-sale	99,208	8,403
Proceeds from maturities and paydowns of investment securities available-for-sale	256,538	301,050
Purchases of investment securities available-for-sale	(768,238)	(337,175)
Net change in partnership investments	(15,146)	(31,298)
Net change in other investments	240	740
Loans sold or participated to others	25,970	10,722
Proceeds from principal payments on direct finance leases	27,072	35,384
Net change in loans and leases	72,195	(596,052)
Net change in equipment owned under operating leases	3,000	16,691
Purchases of premises and equipment	(1,389)	(1,988)
Proceeds from disposal of premises and equipment	125	19
Proceeds from sales of other real estate and repossessions	3,527	6,303
Net Cash Provided by (Used in) Investing Activities	(296,898)	(587,201)
Financing activities:
Net change in demand deposits and savings accounts	806,318	890,031
Net change in time deposits	(229,841)	(350,502)
Net change in short-term borrowings	65,024	19,681
Proceeds from issuance of long-term debt	0	10,000
Payments on long-term debt	(3,288)	(2,710)
Stock issued under stock purchase plans	90	39
Acquisition of treasury stock	(30,067)	0
Net change in noncontrolling interests	1,228	16,877
Cash dividends paid on common stock	(23,405)	(22,376)
Net change in financing activities	586,059	561,040
Net change in cash and cash equivalents	394,235	70,851
Cash and cash equivalents, beginning of year	243,047	83,365
Cash and cash equivalents, end of period	637,282	154,216
Non-cash transactions:
Loans transferred to other real estate and repossessed assets	1,554	2,969
Common stock matching contribution to Employee Stock Ownership and Profit Sharing Plan	715	622
Right of use assets obtained in exchange for lease obligations	$ 698	$ 253

[1] *ASU 2016-13 adopted during the fourth quarter of 2020 therefore September 30, 2020 provision amount reflects the incurred loss method.