CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities
Net Income	$ 77,764	$ 98,739	$ 67,275
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	6,020	6,421	6,353
Amortization of premiums and discounts on securities, net	5,019	2,548	3,196
Amortization of operating lease right-of-use assets	4,362	4,117	0
Other amortization and accretion, net	(8,667)	(2,005)	(1,158)
Stock based compensation	7,304	7,243	7,823
Origination of loans designated for sale	(511,706)	(329,177)	(303,928)
Sale of loans designated for sale	477,178	333,591	326,328
Provision for credit losses	38,179	10,999	11,730
Deferred income taxes	(4,926)	6,791	459
(Gains) losses on sale of securities	(1,096)	(1,031)	485
Gains on sale of loans	(13,930)	(9,794)	(8,961)
Losses (gains) on sale and write-downs of other real estate owned	1,139	(432)	(107)
Losses on disposition of fixed assets	791	511	1,235
Bank owned life insurance death benefits	0	(956)	(280)
Changes in operating assets and liabilities, net of effects from acquired companies:
Net (increase) decrease in other assets	(35,555)	(5,614)	10,331
Net (decrease) increase in other liabilities	18,776	(4,206)	8,827
Net Cash Provided by Operating Activities	60,652	117,745	129,608
Cash Flows From Investing Activities
Maturities and repayments of available-for-sale debt securities	304,064	101,674	141,223
Maturities and repayments of held-to-maturity debt securities	75,861	42,495	58,315
Proceeds from sale of available-for-sale debt securities	96,732	202,724	64,366
Purchases of available-for-sale debt securities	(830,300)	(309,461)	(104,650)
Maturities of time deposits with other banks	2,992	4,501	4,310
Net new loans and principal repayments	(79,100)	(109,614)	(365,816)
Purchases of loans held for investment	0	(270,791)	(19,541)
Proceeds from the sale of other real estate owned	8,521	6,509	10,072
Additions to other real estate owned	(2,557)	0	0
Proceeds from sale of FHLB and Federal Reserve Bank Stock	39,185	74,120	44,731
Purchase of FHLB and Federal Reserve Bank Stock	(28,278)	(75,193)	(51,505)
Proceeds from sale of Visa Class B stock	0	0	21,333
Redemption of bank owned life insurance	0	14,218	4,232
Net cash from bank acquisitions	71,965	0	22,349
Additions to bank premises and equipment	(1,587)	(2,523)	(4,019)
Net Cash Used in Investing Activities	(342,502)	(321,341)	(174,600)
Cash Flows From Financing Activities
Net increase (decrease) in deposits	844,405	407,513	(39,769)
Net increase (decrease) in repurchase agreements	33,488	(128,202)	(1,771)
Net (decrease) increase in FHLB borrowings with original maturities of three months or less	(235,000)	(67,000)	32,000
Repayments of FHLB borrowings with original maturities of more than three months	(115,000)	(63,000)	0
Proceeds from FHLB borrowings with original maturities of more than three months	35,000	65,000	60,000
Stock based employee benefit plans	(1,486)	(2,135)
Stock based employee benefit plans			979
Dividends paid	0	0	0
Net Cash Provided by Financing Activities	561,407	212,176	51,439
Net increase in cash and cash equivalents	279,557	8,580	6,447
Cash and Cash Equivalents at Beginning of Year	124,531	115,951	109,504
Cash and Cash Equivalents at End of Year	404,088	124,531	115,951
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	23,548	46,130	28,301
Cash paid during the period for taxes	27,712	16,000	13,200
Recognition of operating lease right-of-use assets	2,095	30,301	0
Recognition of operating lease liabilities	2,095	34,627	0
Supplemental disclosure of non-cash investing activities:
Transfer of debt securities from held-to-maturity to available-for-sale	0	52,796	0
Transfer from loans to other real estate owned	5,624	5,665	5,549
Transfer from bank premises to other real estate owned	1,289	0	9,168
Transfer from loans held for investment to loans held for sale	$ 0	$ 801	$ 0