Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income	$ 64,814	$ 92,072	$ 68,320
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, and amortization	6,453	6,915	7,014
Amortization of intangible assets	5,724	5,723	3,499
Provision for (benefit from) credit losses	42,813	(1,690)	2,583
Provision for (benefit from) credit losses		(1,690)	2,583
Amortization of investment securities premium, net	2,669	2,547	2,512
Gain on sale of investment securities	(7)	(110)	(207)
Originations of loans for resale	(227,831)	(131,074)	(84,245)
Proceeds from sale of loans originated for resale	234,424	131,689	86,988
Gain on sale of loans	(9,122)	(3,282)	(2,371)
Change in market value of mortgage servicing rights	2,634	1,811	146
Provision for (reversal of) losses on real estate owned	128	(102)	89
Deferred income tax expense	(14,154)	1,692	2,600
Gain on sale or transfer of loans, to real estate owned	(235)	(608)	(408)
Operating lease payments	(4,927)	(4,931)	0
Loss on disposal of fixed assets	67	82	185
Increase in cash value of life insurance	(2,949)	(3,029)	(2,718)
Gain on life insurance death benefit	(498)	(831)	0
(Gain) loss on marketable equity securities	(64)	(86)	64
Equity compensation vesting expense	2,036	1,654	1,462
Change in:
Interest receivable	(1,107)	515	(5,640)
Interest payable	(1,045)	410	1,067
Amortization of operating lease right of use asset	5,393	4,592	0
Other assets and liabilities, net	9,586	(1,153)	10,129
Net cash from operating activities	114,802	102,806	91,069
Investing activities:
Cash acquired in acquisition; net of consideration paid	0	0	30,613
Proceeds from maturities of securities available for sale	167,515	97,993	73,014
Proceeds from maturities of securities held to maturity	89,858	68,346	68,937
Proceeds from sale of available for sale securities	229	127,066	293,279
Purchases of securities available for sale	(617,552)	(37,253)	(436,678)
Net redemption of restricted equity securities	0	0	7,429
Loan origination and principal collections, net	(415,415)	(286,339)	(173,752)
Loans purchased	(41,126)	0	0
Proceeds from sale of real estate owned	570	1,336	2,527
Purchases of premises and equipment	(2,812)	(4,293)	(7,372)
Life insurance proceeds	2,400	3,355	0
Net cash from investing activities	(816,333)	(29,789)	(142,003)
Financing activities:
Net change in deposits	1,138,940	528	365,400
Net change in other borrowings	8,460	2,615	(271,327)
Repurchase of common stock, net	(26,720)	(2,196)	(2,483)
Dividends paid	(26,303)	(24,999)	(18,769)
Exercise of stock options, net	198	9	218
Net cash from financing activities	1,094,575	(24,043)	73,039
Net change in cash and cash equivalents	393,044	48,974	22,105
Cash and cash equivalents at beginning of year	276,507	227,533	205,428
Cash and cash equivalents at end of year	669,551	276,507	227,533
Supplemental disclosure of noncash activities:
Unrealized gain (loss) on securities available for sale	15,796	24,361	(17,627)
Loans transferred to foreclosed assets	766	1,249	1,262
Market value of shares tendered in-lieu of cash to pay for exercise of options and/or related taxes	736	5,108	1,486
Obligations incurred in conjunction with leased assets	4,161	156	0
Supplemental disclosure of cash flow activity:
Cash paid for interest expense	10,502	14,965	11,805
Cash paid for income taxes	29,500	35,050	14,525
Assets acquired in acquisition and goodwill, net	0	0	1,463,100
Liabilities assumed in acquisition	$ 0	$ 0	$ 1,171,968