Fair Value Measurements - Summary of Assets and Liabilities at Carrying Value and Estimated Fair Value on a Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financial Assets:
Cash and due from banks	$ 7,419	$ 7,685	[1]
Federal funds sold	92	625	[1]
Certificates of deposit	3,498	3,746	[1]
Restricted securities	6,684	7,600	[1]
Loans receivable, net	924,268	894,191	[1]
Loans held for sale	268	368	[1]
Accrued interest receivable	3,104	3,172	[1]
Financial Liabilities:
Savings and interest-bearing demand deposits	372,404	359,400	[1]
Time deposits	396,614	368,670	[1]
Securities sold under repurchase agreements	6,323	6,089	[1]
FHLB advances	68,000	100,000	[1]
Subordinated notes, net	6,906	6,893	[1]
Fair Value, Inputs, Level 1
Financial Assets:
Cash and due from banks	7,419	7,685
Interest-earning deposits	23,894	18,981
Federal funds sold	92
Certificates of deposit		3,746
Financial Liabilities:
Noninterest-bearing demand deposits	124,670	114,122
Savings and interest-bearing demand deposits	372,404	359,400
Securities sold under repurchase agreements	6,323	6,089
Fair Value, Inputs, Level 2
Financial Assets:
Federal funds sold		625
Certificates of deposit	3,498
Loans held for sale	268	368
Accrued interest receivable	3,104	3,172
Financial Liabilities:
FHLB advances	67,886	99,727
Fair Value, Inputs, Level 3
Financial Assets:
Restricted securities	6,684	7,600
Loans receivable, net	911,497	877,114
Financial Liabilities:
Time deposits	398,254	369,347
Subordinated notes, net	7,032	7,046
Carrying Value
Financial Assets:
Cash and due from banks	7,419	7,685
Interest-earning deposits	23,894	18,981
Federal funds sold	92	625
Certificates of deposit	3,498	3,746
Restricted securities	6,684	7,600
Loans receivable, net	924,268	894,191
Loans held for sale	268	368
Accrued interest receivable	3,104	3,172
Financial Liabilities:
Noninterest-bearing demand deposits	124,670	114,122
Savings and interest-bearing demand deposits	372,404	359,400
Time deposits	396,614	368,670
Securities sold under repurchase agreements	6,323	6,089
FHLB advances	68,000	100,000
Subordinated notes, net	6,906	6,893
Fair Value
Financial Assets:
Cash and due from banks	7,419	7,685
Interest-earning deposits	23,894	18,981
Federal funds sold	92	625
Certificates of deposit	3,498	3,746
Restricted securities	6,684	7,600
Loans receivable, net	911,497	877,114
Loans held for sale	268	368
Accrued interest receivable	3,104	3,172
Financial Liabilities:
Noninterest-bearing demand deposits	124,670	114,122
Savings and interest-bearing demand deposits	372,404	359,400
Time deposits	398,254	369,347
Securities sold under repurchase agreements	6,323	6,089
FHLB advances	67,886	99,727
Subordinated notes, net	$ 7,032	$ 7,046

[1] Derived from audited December 31, 2018 Consolidated Financial Statements.