Capital Requirements and Restriction on Retained Earnings - Actual Capital Levels and Minimum Required Capital Levels (Detail) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Consolidated [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk Based Capital, Actual, Amount	$ 429,080	$ 395,125
Tier I Risk Based Capital, Actual, Amount	318,322	293,164
CET1 Risk Based Capital, Actual, Amount	288,895	263,736
Leverage, Actual, Amount	$ 318,322	$ 293,164
Total Risk Based Capital, Actual, Ratio	0.144	0.141
Tier I Risk Based Capital, Actual, Ratio	0.107	0.104
CET1 Risk Based Capital, Actual, Ratio	0.097	0.094
Leverage, Actual, Ratio	0.088	0.087
Total Risk Based Capital , For Capital Adequacy Purposes, Amount	$ 237,604	$ 217,681
Tier I Risk Based Capital, For Capital Adequacy Purposes, Amount	178,203	163,261
CET1 Risk Based Capital, For Capital Adequacy Purposes, Amount	133,652	122,446
Leverage, For Capital Adequacy Purposes, Amount	$ 145,489	$ 131,479
Total Risk Based Capital , For Capital Adequacy Purposes, Ratio	0.080	0.080
Tier I Risk Based Capital, For Capital Adequacy Purposes, Ratio	0.060	0.060
CET1 Risk Based Capital, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Leverage, For Capital Adequacy Purposes, Ratio	0.04	0.040
Civista [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk Based Capital, Actual, Amount	$ 400,047	$ 366,377
Tier I Risk Based Capital, Actual, Amount	363,033	337,866
CET1 Risk Based Capital, Actual, Amount	363,033	337,866
Leverage, Actual, Amount	$ 363,033	$ 337,866
Total Risk Based Capital, Actual, Ratio	0.135	0.129
Tier I Risk Based Capital, Actual, Ratio	0.123	0.119
CET1 Risk Based Capital, Actual, Ratio	0.123	0.119
Leverage, Actual, Ratio	0.100	0.100
Total Risk Based Capital , For Capital Adequacy Purposes, Amount	$ 236,568	$ 219,357
Tier I Risk Based Capital, For Capital Adequacy Purposes, Amount	177,426	164,517
CET1 Risk Based Capital, For Capital Adequacy Purposes, Amount	133,069	123,388
Leverage, For Capital Adequacy Purposes, Amount	$ 145,245	$ 131,240
Total Risk Based Capital , For Capital Adequacy Purposes, Ratio	0.080	0.080
Tier I Risk Based Capital, For Capital Adequacy Purposes, Ratio	0.06	0.060
CET1 Risk Based Capital, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Leverage, For Capital Adequacy Purposes, Ratio	0.040	0.040
Total Risk Based Capital , To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	$ 295,710	$ 274,196
Tier I Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	236,568	219,357
CET1 Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	192,211	178,227
Leverage, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	$ 181,556	$ 164,050
Total Risk Based Capital , To Be Well Capitalized Under Prompt Corrective Action Purposes, Ratio	0.100	0.100
Tier I Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Ratio	0.08	0.080
CET1 Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Ratio	6.50%	6.50%
Leverage, To Be Well Capitalized Under Prompt Corrective Action Purposes, Ratio	0.050	0.050