ACCOUNTING POLICIES (Narrative) (Details)					3 Months Ended		6 Months Ended
	Jun. 01, 2022 USD ($)	May 31, 2022 USD ($)	Dec. 31, 2021 USD ($)		Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) property segment	Jun. 30, 2021 USD ($)	Apr. 28, 2022	Mar. 31, 2022 USD ($)	Sep. 30, 2021	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Organization And Significant Accounting Policies [Line Items]
Number of branches | property							34
Financing receivable, allowance for credit loss			$ 29,105,000	[1]	$ 30,209,000	$ 31,265,000	$ 30,209,000	$ 31,265,000		$ 29,379,000		$ 34,893,000	$ 36,345,000
Cumulative effect adjustment			411,881,000	[1]	398,637,000	406,940,000	$ 398,637,000	406,940,000		$ 404,195,000		$ 397,986,000	$ 390,554,000
Number of reportable segments | segment							1
Net income					5,009,000	10,275,000	$ 9,602,000	19,658,000
Gain (loss) on sale of mortgage loans					593,000		593,000	0
Salaries and benefits					10,573,000	$ 8,810,000	20,198,000	$ 18,182,000
Securities available for sale, at fair value			271,332,000	[1]	257,180,000		257,180,000
Loans held for investment			2,339,986,000	[1]	$ 2,628,797,000		$ 2,628,797,000
Southern Trust Mortgage [Member]
Organization And Significant Accounting Policies [Line Items]
Notes receivable			8,500,000
Southern Trust Mortgage [Member]
Organization And Significant Accounting Policies [Line Items]
Payments to acquire equity method investments			$ 1,600,000
Common Stock | Southern Trust Mortgage [Member]
Organization And Significant Accounting Policies [Line Items]
Percentage of equity investment and preferred stock of STM											43.28%
Preferred Stock | Southern Trust Mortgage [Member]
Organization And Significant Accounting Policies [Line Items]
Percentage of equity investment and preferred stock of STM					100.00%		100.00%				100.00%
Paycheck Protection Program Loans [Member]
Organization And Significant Accounting Policies [Line Items]
Financing receivable, allowance for credit loss					$ 0		$ 0
Primis Mortgage (f.k.a. SeaTrust)
Organization And Significant Accounting Policies [Line Items]
Net income					$ (100,000)		$ (100,000)
Payments to acquire business	$ 7,000,000	$ 7,000,000
Short term borrowings	$ 19,254,000	$ 19,254,000
Voting interest agreed to acquire (as a percent)									100.00%
Capital Stock Acquired (as a percent)		100.00%
Virginia [Member]
Organization And Significant Accounting Policies [Line Items]
Number of branches | property							32
Maryland
Organization And Significant Accounting Policies [Line Items]
Number of branches | property							2

[1] Derived from audited consolidated financial statements