Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 73,612	$ 67,109	$ 51,564
Proceeds from sales of loans held for sale	131,014	92,422	138,659
Originations of loans held for sale	(135,937)	(83,806)	(126,215)
Items not requiring (providing) cash
Depreciation	9,557	9,118	9,120
Amortization	2,068	2,291	2,731
Compensation expense for stock option grants	922	737	564
Provision for loan losses	6,150	7,150	9,100
Net gains on loan sales	(2,607)	(1,788)	(3,150)
Net realized (gains) losses on available-for-sale securities	62	(2)	0
Loss on sale of premises and equipment	77	193	297
(Gain) loss on sale/write-down of other real estate and repossessions	316	1,886	(449)
Gain on Sales of Business Units	0	(7,414)	0
Gain realized on termination of loss sharing agreements	0	0	(7,705)
Accretion of deferred income, premiums, discounts and other	(3,899)	(2,918)	(1,947)
(Gain) loss on derivative interest rate products	104	(25)	(28)
Deferred income taxes	1,074	(4,450)	9,423
Interest receivable	(82)	(1,110)	(463)
Prepaid expenses and other assets	(1,336)	3,002	(5,227)
Accrued expenses and other liabilities	2,725	280	1,821
Income taxes refundable/payable	2,599	11,520	(15,278)
Net cash provided by operating activities	86,419	94,195	62,817
Investing Activities
Net change in loans	(81,320)	(147,945)	136,596
Purchase of loans	(97,162)	(128,038)	(133,018)
Cash received from FDIC loss sharing reimbursements	0	0	16,246
Cash paid for sale of business units	0	(50,356)	0
Purchase of premises and equipment	(11,789)	(9,317)	(7,404)
Proceeds from sale of premises and equipment	204	2,328	565
Proceeds from sale of other real estate and repossessions	15,244	20,426	33,640
Capitalized costs on other real estate owned	(121)	(153)	(117)
Proceeds from maturities, calls and repayments of held-to-maturity securities	0	130	117
Proceeds from sale of available-for-sale securities	53,695	502	0
Proceeds from maturities, calls and repayments of available-for-sale securities	34,769	25,734	36,754
Purchase of available-for-sale securities	(207,634)	(93,378)	(3,852)
Redemption (purchase) of Federal Home Loan Bank stock	(1,035)	(1,256)	1,852
Net cash provided by (used in) investing activities	(295,149)	(381,323)	81,379
Financing Activities
Net increase (decrease) in certificates of deposit	129,748	242,955	(114,714)
Net increase (decrease) in checking and savings accounts	105,400	(53,956)	34,796
Proceeds from Federal Home Loan Bank advances	0	2,621,500	1,420,500
Repayments of Federal Home Loan Bank advances	0	(2,749,000)	(1,324,435)
Increase (decrease) in short term borrowings and other interest-bearing liabilities	14,346	200,843	(188,888)
Advances from (to) borrowers for taxes and insurance	2,392	(227)	676
Purchase of the company's common stock	(849)	(903)	0
Dividends paid	(29,052)	(15,819)	(12,894)
Stock options exercised	4,158	2,224	3,247
Net cash provided by (used in) financing activities	226,143	247,617	(181,712)
Increase (Decrease) in Cash and Cash Equivalents	17,413	(39,511)	(37,516)
Cash and Cash Equivalents, Beginning of Year	202,742	242,253	279,769
Cash and Cash Equivalents, End of Year	$ 220,155	$ 202,742	$ 242,253