Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 23,618		$ 6,579
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,265		1,356
Deferred taxes	(643)		(2,037)
Stock-based compensation	213		228
Provision for credit losses	(2,499)	$ 1,000	12,707	$ 16,047
Write-downs of other real estate owned and other repossessed assets	154		458
Gains on sale of mortgage loans held for sale	(2,433)		(483)
Securities gains, net	(60)		(481)
Change in fair market value of equity securities	228		232
Gains on sale of assets, net	(214)		(3)
Proceeds from sale of mortgage loans held for sale	109,014		23,032
Funding of mortgage loans held for sale	(101,070)		(22,785)
Amortization of securities premiums and discounts, net	1,893		1,271
Change in cash surrender value of bank owned life insurance	(337)		(340)
Payment of operating lease liabilities	(445)		(444)
Mortgage servicing rights:
Fair value adjustments	(780)		926
New servicing assets created	(736)		(144)
Changes in:
Accrued interest receivable	630		156
Other assets	1,634		(1,173)
Accrued interest payable	122		608
Other liabilities	2,152		(5,939)
Net cash provided by operating activities	31,706		13,724
Securities available-for-sale (AFS):
Purchase of AFS securities	(304,167)		(126,748)
Proceeds from sales of AFS securities	1,080		21,746
Proceeds from prepayments, calls, and maturities of AFS securities	129,804		72,243
Securities held-to-maturity (HTM):
Proceeds from maturities of HTM securities	0		517
Change in loans, net	15,747		(41,183)
Purchase of premises and equipment	(403)		(423)
Proceeds from sale and retirement of premises and equipment	812		0
Purchase (redemption) of stock by Federal Home Loan Bank	77		(880)
Proceeds from sale of other real estate owned and repossessed assets	762		116
Net cash used in investing activities	(156,288)		(74,612)
Cash flows from financing activities:
Change in deposits, net	217,690		(10,464)
Change in repurchase agreements and federal funds purchased, net	(1,627)		6,992
Proceeds from Federal Home Loan Bank advances	0		25,000
Payments on advances from Federal Home Loan Bank	(5)		(25,004)
Payment of finance lease liabilities	(3)		(3)
Issuance of common stock	238		232
Repurchase of common stock	0		(1,099)
Dividends paid	(6,841)		(6,747)
Net cash provided by (used in) financing activities	209,452		(11,093)
Net increase (decrease) in cash and cash equivalents	84,870		(71,981)
Cash and cash equivalents at beginning of period	338,235		264,683	264,683
Cash and cash equivalents at end of period	423,105	$ 338,235	192,702	$ 338,235
Supplemental disclosures:
Income taxes paid	87		0
Interest paid	3,847		7,848
Non-cash activities:
Loans to facilitate the sale of other real estate owned and repossessed assets	381		718
Common stock dividends accrued, paid in subsequent quarter	242		224
Real estate acquired in settlement of loans	$ (136)		$ 1,625