River Financial Corporation (Parent Company Only) Financial Information - Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Condensed Income Statements Captions [Line Items]
Total interest income	$ 132,261	$ 88,874
Interest expense - note payable	520
Interest expense - subordinated debentures	1,669	1,679
Legal and other professional fees	1,009	809
Data processing expense	4,051	3,992
Other expenses	8,855	8,390
Applicable income tax benefit	6,848	7,948
Net income	26,739	27,929
River Financial Corporation
Condensed Income Statements Captions [Line Items]
Other income	719
Total interest income	719
Interest expense - note payable	520
Interest expense - subordinated debentures	1,669	1,679
Legal and other professional fees	137	104
Data processing expense	1	5
Stockholders' meeting expense	32	27
Other expenses	324	290
Total expenses	2,683	2,105
Net loss before tax benefit	(1,964)	(2,105)
Applicable income tax benefit	(491)	(526)
Net loss before undistributed net income of River Bank & Trust	(1,473)	(1,579)
Equity in undistributed net income of River Bank & Trust	28,212	29,508
Net income	$ 26,739	$ 27,929