CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net Income	$ 73,447	$ 105,333	$ 107,498
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	56,718	14,533	12,531
Deferred Income Taxes and Tax Credits	(8,217)	2,292	3,473
Depreciation and amortization	11,653	10,370	8,046
Net gains on securities and other assets	(18,807)	(10,671)	(21,540)
Net amortization of premiums and discounts on securities	6,183	3,892	3,083
Income from increase in cash surrender value of bank owned life insurance	(6,288)	(5,998)	(5,808)
Mortgage loans originated for sale	(410,715)	(251,428)	(165,898)
Proceeds from Sale of Mortgage Loans Held-for-sale	408,877	251,968	177,287
Increase in interest receivable	(10,735)	423	(2,561)
Increase (decrease) in interest payable	(879)	(256)	383
(Increase) decrease in income taxes payable	(887)	1,484	(1,926)
Distribution from unconsolidated subsidiary	0	0	9,000
Other—net	5,349	(14,310)	11,695
Net cash provided by operating activities	105,699	107,632	135,263
Transactions with securities held to maturity:
Proceeds from Sale and Maturity of Held-to-maturity Securities	0	948	0
Proceeds from maturities and redemptions	118,905	54,632	47,614
Purchases	(85,679)	(200)	(20,650)
Transactions with securities available for sale:
Proceeds from sales	0	0	15,939
Proceeds from maturities and redemptions	472,282	189,194	140,707
Purchases	(411,178)	(138,670)	(331,969)
Purchases of FHLB stock	(22,231)	(36,850)	(52,107)
Proceeds from the redemption of FHLB stock	26,766	52,215	51,488
Proceeds from bank owned life insurance	1,444	557	2,140
Proceeds from the sale of loans	41,141	37,534	40,783
Proceeds from sales of other assets	5,531	6,822	4,477
Acquisition, net of cash acquired	0	332,468	705
Net increase in loans	(622,504)	(358,328)	(237,276)
Purchases of premises and equipment	(7,615)	(17,380)	(9,599)
Net cash (used in) provided by investing activities	(483,138)	122,942	(347,748)
Financing Activities
Net increase (decrease) in federal funds purchased	0	(11,000)	11,000
Net (decrease) increase in other short-term borrowings	(84,480)	(508,970)	3,357
Net increase in deposits	761,398	308,783	176,558
Repayments of other long-term debt	(659)	(634)	(23,598)
Proceeds from Issuance of Long-term Debt	0	50,000	98,026
Repayments of Long-term Capital Lease Obligations	430	402	373
Dividends paid	(42,982)	(39,394)	(34,849)
Proceeds from reissuance of treasury stock	222	211	208
Purchase of treasury stock	(20,905)	(6,259)	(26,189)
Net cash provided by (used in) financing activities	612,164	(207,665)	204,140
Net (decrease) increase in cash and cash equivalents	234,725	22,909	(8,345)
Cash and cash equivalents at January 1	121,856	98,947	107,292
Cash and cash equivalents at December 31	$ 356,581	$ 121,856	$ 98,947