Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Activities
Net income per consolidated statements of income	$ 51,962	$ 22,218
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense, net	(19,868)	27,364
Depreciation and amortization	11,126	8,996
Net amortization of securities	5,430	1,918
Gains on sales of loans, net	(25,796)	(7,085)
Compensation expense, long-term incentive plan	2,181	1,394
Deferred income tax provision	9,000	(11,600)
Proceeds from sales of loans held for sale	685,151	324,167
Purchases and originations of loans held for sale	(643,175)	(416,687)
Originations of mortgage servicing rights	(7,978)	(3,649)
Earnings on bank-owned life insurance	(1,216)	(1,292)
Net change in other assets	21,070	(49,822)
Net change in other liabilities	9,096	(204)
Other operating activities, net	(13,640)	25,119
Net cash from operating activities	83,343	(79,163)
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	44,688	34,459
Proceeds from maturities, prepayments and calls of securities available for sale	217,783	86,129
Purchases of securities available for sale	(590,517)	(278,691)
Net proceeds from bank-owned life insurance	1,818	280
Net change in federal funds sold and securities purchased under reverse repurchase agreements	50	(2,000)
Net change in member bank stock	(3)	(107)
Net change in LHFI and PPP loans	(226,385)	(162,097)
Purchases of premises and equipment	(8,152)	(4,154)
Proceeds from sales of other real estate	909	3,671
Purchases of software	(818)	(1,805)
Investments in tax credit and other partnerships	(7,149)	(141)
Purchase of insurance book of business	0	(3,097)
Net cash from investing activities	(567,776)	(327,553)
Financing Activities
Net change in deposits	334,676	330,207
Net change in federal funds purchased and securities sold under repurchase agreements	(3,528)	165,801
Net change in short-term borrowings	(4,220)	(127)
Payments on long-term FHLB advances	(4)	(17)
Payments under finance lease obligations	(354)	(459)
Common stock dividends	(14,685)	(14,706)
Repurchase and retirement of common stock	(4,185)	(27,538)
Shares withheld to pay taxes, long-term incentive plan	(1,230)	(1,020)
Net cash from financing activities	306,470	452,141
Net change in cash and cash equivalents	(177,963)	45,425
Cash and cash equivalents at beginning of period	1,952,504	358,916
Cash and cash equivalents at end of period	$ 1,774,541	$ 404,341