Business Combination and Asset Purchase - Additional Information (Detail) $ / shares in Units, $ in Thousands			3 Months Ended
	Nov. 16, 2020 USD ($) shares	Jan. 01, 2019 USD ($) Office $ / shares shares	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) shares	Nov. 30, 2020 USD ($) Client
Business Acquisition [Line Items]
Common stock, shares outstanding | shares			12,230,000		12,230,000
Recognition of core deposit intangible asset with acquired purchase			$ 3,900
Remaining economic useful life			7 years
Goodwill			$ 47,340		$ 47,340
Amortization expense			140	$ 182
Amortization expense for 2021			560
Custar [Member]
Business Acquisition [Line Items]
Amortization expense				$ 42
Customer Lists [Member]
Business Acquisition [Line Items]
Amortization expense			31
Amortization expense for 2021			123
Bank of Geneva [Member]
Business Acquisition [Line Items]
Number of full-service offices | Office		6
Limberlost Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Common stock issued in exchange of each outstanding share | shares		1,830,000
Cash payment for exchange of each share | $ / shares		$ 8,465.00
Common stock, shares outstanding | shares		1,000
Share price | $ / shares		$ 38.49
Total consideration for acquisition		$ 78,900
Cash paid for acquisition		8,500
Stock issued for acquisition		70,400
Goodwill		43,300
Limberlost Bancshares, Inc. [Member] | Core Deposits [Member]
Business Acquisition [Line Items]
Recognition of core deposit intangible asset with acquired purchase		$ 3,900
Remaining economic useful life		7 years
Adams County Financial Resources
Business Acquisition [Line Items]
Common stock issued in exchange of each outstanding share | shares	40,049
Total consideration for acquisition	$ 825
Stock issued for acquisition	825
Assets under management amount						$ 83,000
Number of clients assets under management | Client						450
Increase to noninterest income	500
Adams County Financial Resources | Customer Lists [Member]
Business Acquisition [Line Items]
Recognition of core deposit intangible asset with acquired purchase	$ 800
Remaining economic useful life	6 years 6 months
Amortization expense for 2021			$ 123