Parent Only Financial Information - Parent Only Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flows from Operating Activities:
Net Income	$ 29,709	$ 30,075	$ 48,799
Shares Issued Under the Directors’ Stock Plan	495	218	408
Net Cash Provided By Operating Activities	34,469	20,580	59,713
Cash Flows from Financing Activities:
Shares Issued for Stock Option Exercises, net	433	96	631
Shares Issued Under the Employee Stock Purchase Plan	291	120	477
Shares Issued for Dividend Reinvestment Plans	0	472	1,904
Purchase of Treasury Stock	(6,790)	(3,608)	(2,872)
Net Cash Provided (Used) By Financing Activities	66,491	139,946	(59,687)
Net Increase (Decrease) in Cash and Cash Equivalents	12,010	77,876	(393,036)
Cash and Cash Equivalents at Beginning of Year	142,536	64,660	457,696
Cash and Cash Equivalents at End of Year	154,546	142,536	64,660
Interest on Deposits and Borrowings	84,489	51,828	5,752
Arrow
Cash Flows from Operating Activities:
Net Income	29,709	30,075	48,799
Undistributed Net Income of Subsidiaries	(5,151)	(9,388)	(29,849)
Shares Issued Under the Directors’ Stock Plan	495	218	408
Changes in Other Assets and Other Liabilities	(1,673)	(229)	(754)
Net Cash Provided By Operating Activities	23,380	20,676	18,604
Cash Flows from Financing Activities:
Shares Issued for Stock Option Exercises, net	433	96	631
Shares Issued Under the Employee Stock Purchase Plan	291	120	477
Shares Issued for Dividend Reinvestment Plans	0	472	1,904
Purchase of Treasury Stock	(6,790)	(3,608)	(2,872)
Cash Dividends Paid	(18,286)	(17,983)	(17,444)
Net Cash Provided (Used) By Financing Activities	(24,352)	(20,903)	(17,304)
Net Increase (Decrease) in Cash and Cash Equivalents	(972)	(227)	1,300
Cash and Cash Equivalents at Beginning of Year	1,305	1,532	232
Cash and Cash Equivalents at End of Year	333	1,305	1,532
Interest on Deposits and Borrowings	$ 685	$ 685	$ 685