Capital Requirements and Restriction on Retained Earnings - Actual Capital Levels and Minimum Required Capital Levels (Detail) $ in Thousands	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Consolidated [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk Based Capital, Actual, Amount	$ 456,499	$ 429,080
Tier I Risk Based Capital, Actual, Amount	341,811	318,322
CET1 Risk Based Capital, Actual, Amount	312,384	288,895
Leverage, Actual, Amount	$ 341,811	$ 318,322
Total Risk Based Capital, Actual, Ratio	0.139	0.144
Tier I Risk Based Capital, Actual, Ratio	0.104	0.107
CET1 Risk Based Capital, Actual, Ratio	0.095	0.097
Leverage, Actual, Ratio	0.086	0.088
Total Risk Based Capital , For Capital Adequacy Purposes, Amount	$ 261,904	$ 237,604
Tier I Risk Based Capital, For Capital Adequacy Purposes, Amount	196,428	178,203
CET1 Risk Based Capital, For Capital Adequacy Purposes, Amount	147,321	133,652
Leverage, For Capital Adequacy Purposes, Amount	$ 158,679	$ 145,489
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	0.040	0.04
Civista [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Risk Based Capital, Actual, Amount	$ 420,363	$ 400,047
Tier I Risk Based Capital, Actual, Amount	379,447	363,033
CET1 Risk Based Capital, Actual, Amount	379,447	363,033
Leverage, Actual, Amount	$ 379,447	$ 363,033
Total Risk Based Capital, Actual, Ratio	0.129	0.135
Tier I Risk Based Capital, Actual, Ratio	0.116	0.123
CET1 Risk Based Capital, Actual, Ratio	0.116	0.123
Leverage, Actual, Ratio	0.096	0.100
Total Risk Based Capital , For Capital Adequacy Purposes, Amount	$ 261,693	$ 236,568
Tier I Risk Based Capital, For Capital Adequacy Purposes, Amount	196,270	177,426
CET1 Risk Based Capital, For Capital Adequacy Purposes, Amount	147,202	133,069
Leverage, For Capital Adequacy Purposes, Amount	$ 157,823	$ 145,245
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	0.06
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	$ 327,116	$ 295,710
Tier I Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	261,693	236,568
CET1 Risk Based Capital, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	212,626	192,211
Leverage, To Be Well Capitalized Under Prompt Corrective Action Purposes, Amount	$ 197,278	$ 181,556
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	0.080	0.08
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