Condensed Parent Company Only Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 705,618	$ 377,214
Other assets	141,758	141,041
Total assets	7,861,285	7,628,268
Liabilities and Stockholders' Equity
Subordinated indebtedness, net	157,417	157,181
Accrued expenses and other liabilities	93,163	88,014
Total liabilities	7,131,074	6,981,118
Stockholders' Equity
Common stock	118,733	117,532
Additional paid‑in capital	242,114	237,341
Retained earnings	363,635	266,628
Accumulated other comprehensive income	5,729	25,649
Total liabilities and stockholders' equity	7,861,285	7,628,268
Origin Bancorp, Inc.
Assets
Cash and cash equivalents	28,904	42,908
Investment in affiliates/subsidiaries	774,840	684,410
Other assets	16,343	10,198
Total assets	820,087	737,516
Liabilities and Stockholders' Equity
Subordinated indebtedness, net	88,405	88,258
Accrued expenses and other liabilities	1,471	2,108
Total liabilities	89,876	90,366
Stockholders' Equity
Common stock	118,733	117,532
Additional paid‑in capital	242,114	237,341
Retained earnings	363,635	266,628
Accumulated other comprehensive income	5,729	25,649
Total stockholders' equity	730,211	647,150
Total liabilities and stockholders' equity	$ 820,087	$ 737,516