Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 41,711	$ 26,751
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization	8,228	6,992
Change In Unamortized Net Loan Costs And Premiums	(10,318)	(735)
Provision for credit losses	(2,500)	25,000
Deferred income tax expense	567	3,108
Net unrealized (gain) loss on equity securities	(316)	1,801
Gain (Loss) on Disposition of Property Plant Equipment	4	420
Realized gain on sale leaseback transaction	(145)	(145)
Stock based compensation	1,150	850
Increase in cash surrender value of life insurance policies	(1,323)	(1,276)
Gain Realized on Life Insurance Policies	(258)	(357)
Operating Lease, Payments	(3,077)	(2,926)
Change in Fair Value on Loans Held for Sale	1,764	(255)
Net change in:
Trading assets	(431)	(68)
Loans held for sale	14,708	(10,194)
Other assets	70,901	(151,830)
Increase (Decrease) in Other Operating Liabilities	(53,201)	92,461
Total adjustments	25,753	(37,154)
Net cash provided by (used in) operating activities	67,464	(10,403)
Cash flows used in investing activities
Increase (Decrease) in Equity Securities, FV-NI	(124)	(108)
Proceeds from maturities and principal repayments of securities available for sale	26,092	31,280
Payments to Acquire Debt Securities, Available-for-sale	(223,986)	(30,095)
Proceeds from maturities and principal repayments of securities held to maturity	68,497	48,183
Purchases of securities held to maturity	(149,453)	(84,824)
Net purchases of Federal Home Loan Bank stock	0	(8,850)
Investments in low income housing projects	(6,632)	(5,934)
Purchases of life insurance policies	(40,093)	(93)
Proceeds from Life Insurance Policy	576	1,326
Net (increase) decrease in loans	153,150	(41,283)
Purchases of bank premises and equipment	(2,524)	(1,749)
Proceeds from the sale of bank premises and equipment	4	9
Net cash used in investing activities	(174,493)	(92,138)
Cash flows provided by financing activities
Net decrease in time deposits	(82,569)	(125,396)
Net increase in other deposits	682,938	394,438
Increase (Decrease) in Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Net	0	257,826
Increase Decrease in Federal Home Loan Bank Advances Long Term	0	(15,000)
Repayments of Debt	(4,688)
Repayments of long-term debt, net of issuance costs		0
Net Purchases from Stock Options Exercised	(57)
Net proceeds from exercise of stock options		0
Restricted stock awards issued, net of awards surrendered	(1,220)	(1,132)
Proceeds from shares issued under direct stock purchase plan	492	560
Payments for shares repurchased under share repurchase program	0	(73,226)
Common dividends paid	(15,164)	(15,126)
Net cash provided by financing activities	579,732	422,944
Net increase in cash and cash equivalents	472,703	320,403
Cash and cash equivalents at beginning of year	1,296,636	150,974
Cash and cash equivalents at end of period	1,769,339	471,377
Supplemental schedule of noncash activities
Net increase in capital commitments relating to low income housing project investments	24,014	14,394
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 0	$ 2,223