Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net income per consolidated statements of income	$ 29,211	$ 51,962
Adjustments to reconcile net income to net cash provided by operating activities:
PCL	(1,966)	(19,868)
Depreciation and amortization	10,441	11,126
Net amortization of securities	3,711	5,430
Gains on sales of loans, net	(8,315)	(25,796)
Compensation expense, long-term incentive plan	1,245	2,181
Deferred income tax provision	9,300	9,000
Proceeds from sales of loans held for sale	381,947	685,151
Purchases and originations of loans held for sale	(326,475)	(643,175)
Originations of mortgage servicing rights	(5,128)	(7,978)
Earnings on bank-owned life insurance	(1,188)	(1,216)
Net change in other assets	(15,626)	21,070
Net change in other liabilities	7,575	9,096
Other operating activities, net	(22,864)	(13,640)
Net cash from operating activities	61,868	(83,343)
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	38,822	44,688
Proceeds from maturities, prepayments and calls of securities available for sale	137,766	217,783
Purchases of securities held to maturity	(303,525)
Purchases of securities available for sale	(76,341)	(590,517)
Net proceeds from bank-owned life insurance		1,818
Net change in federal funds sold and securities purchased under reverse repurchase agreements		50
Net change in member bank stock	(68)	(3)
Net change in LHFI and PPP loans	(134,451)	(226,385)
Purchases of premises and equipment	(5,987)	(8,152)
Proceeds from sales of premises and equipment	1,129
Proceeds from sales of other real estate	1,413	909
Purchases of software	(1,832)	(818)
Investments in tax credit and other partnerships	(1,454)	(7,149)
Net cash from investing activities	(344,528)	(567,776)
Financing Activities
Net change in deposits	26,132	334,676
Net change in federal funds purchased and securities sold under repurchase agreements	(68,078)	(3,528)
Net change in short-term borrowings		(4,220)
Payments on long-term FHLB advances	(4)	(4)
Payments under finance lease obligations	(366)	(354)
Common stock dividends	(14,186)	(14,685)
Repurchase and retirement of common stock	(9,094)	(4,185)
Shares withheld to pay taxes, long-term incentive plan	(1,009)	(1,230)
Net cash from financing activities	(66,605)	306,470
Net change in cash and cash equivalents	(349,265)	(177,963)
Cash and cash equivalents at beginning of period	2,266,829	1,952,504
Cash and cash equivalents at end of period	$ 1,917,564	$ 1,774,541