Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Equity Incentive Plan - Additional Information (Detail) - USD ($) $ in Thousands				9 Months Ended
	May 21, 2019	Sep. 25, 2018	May 17, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected future compensation expense				$ 577
Weighted average remaining life of grants related to unvested awards not yet recognized				2 years 6 months
Civista Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common shares granted	8,946	867	6,204
Share based compensation - Civista BOD	$ 196	$ 21	$ 144
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares vesting service period				3 years
2014 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares under stock option plan authorized for issuance						375,000
Number of shares available for grant under stock option plan				240,001
Options granted				0	0
Share based compensation expense				$ 256
Expected future compensation expense				$ 577
Weighted average remaining life of grants related to unvested awards not yet recognized				2 years 6 months