Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 92,072	$ 68,320	$ 40,554
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, and amortization	6,915	7,014	6,787
Amortization of intangible assets	5,723	3,499	1,389
Provision for (benefit from) loan losses	(1,690)	2,583	89
Amortization of investment securities premium, net	2,547	2,512	3,200
Gain on sale of investment securities	(110)	(207)	(961)
Originations of loans for resale	(131,074)	(84,245)	(114,107)
Proceeds from sale of loans originated for resale	131,689	86,988	114,788
Gain on sale of loans	(3,282)	(2,371)	(3,109)
Change in market value of mortgage servicing rights	1,811	146	718
(Reversal of) provision for losses on real estate owned	(102)	89	162
Deferred income tax expense	1,692	2,600	12,473
Gain on sale or transfer of loans, to real estate owned	(608)	(408)	(711)
Operating lease payments	(4,931)
Loss on disposal of fixed assets	82	185	142
Increase in cash value of life insurance	(3,029)	(2,718)	(2,685)
Gain on life insurance death benefit	(831)		(108)
(Gain) loss on marketable equity securities	(86)	64
Equity compensation vesting expense	1,654	1,462	1,586
Change in
Interest receivable	515	(5,640)	(1,745)
Interest payable	410	1,067	112
Amortization of operating lease ROUA	4,592
Other assets and liabilities, net	(1,153)	10,129	(3,193)
Net cash from operating activities	102,806	91,069	55,381
Investing activities
Cash acquired in acquisition, net of consideration paid	0	30,613
Proceeds from maturities of securities available for sale	97,993	73,014	63,942
Proceeds from maturities of securities held to maturity	68,346	68,937	86,371
Proceeds from sale of available for sale securities	127,066	293,279	25,757
Purchases of securities available for sale	(37,253)	(436,678)	(265,806)
Net redemption of restricted equity securities	0	7,429
Loan origination and principal collections, net	(286,339)	(173,752)	(259,404)
Proceeds from sale of real estate owned	1,336	2,527	2,872
Proceeds from sale of premises and equipment	0	63	3,338
Purchases of premises and equipment	(4,293)	(7,435)	(15,164)
Life insurance proceeds	3,355		649
Net cash from investing activities	(29,789)	(142,003)	(357,445)
Financing activities
Net change in deposits	528	365,400	113,571
Net change in other borrowings	2,615	(271,327)	104,673
Repurchase of common stock, net	(2,196)	(2,483)	(1,629)
Dividends paid	(24,999)	(18,769)	(15,131)
Exercise of stock options	9	218	396
Net cash from financing activities	(24,043)	73,039	201,880
Net change in cash and cash equivalents	48,974	22,105	(100,184)
Cash and cash equivalents at beginning of year	227,533	205,428	305,612
Cash and cash equivalents at end of year	276,507	227,533	205,428
Supplemental disclosure of noncash activities
Unrealized (loss) gain on securities available for sale	24,361	(17,627)	5,461
Loans transferred to foreclosed assets	1,249	1,262	1,563
Market value of shares tendered in-lieu of cash to pay for exercise of options and/or related taxes	5,108	1,486	2,225
Obligations incurred in conjunction with leased assets	156
Supplemental disclosure of cash flow activity
Cash paid for interest expense	14,965	11,805	5,609
Cash paid for income taxes	35,050	14,525	21,170
Assets acquired in acquisition and goodwill, net	0	1,463,100	0
Liabilities assumed in acquisition	$ 0	$ 1,171,968	$ 0