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CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands		9 Months Ended	12 Months Ended
	Nov. 27, 2018	Sep. 30, 2020	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($) $ / shares
Statement of Stockholders' Equity [Abstract]
Cash dividends per common share (usd per share) | $ / shares			$ 0.92	$ 0.80	$ 0.64
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member		us-gaap:AccountingStandardsUpdate201613Member
Stock split ratio	2
Stock issued in payment of director fees | $			$ 217	$ 231	$ 204

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