Fair Value - Summary of Assets and Liabilities at Carrying Value and Estimated Fair Value on a Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial Assets:
Cash and due from banks	$ 7,685	$ 9,396
Certificates of deposit	3,746	3,224
Federal funds sold	625	6,961
Restricted securities	7,600	5,787
Loans receivable, net	894,191	758,726
Loans held for sale	368	1,651
Accrued interest receivable	3,172	3,194
Financial Liabilities:
Noninterest-bearing liabilities	114,122	103,037
Savings and other interest-bearing deposits	359,400	299,820
Time deposits	368,670	358,989
Securities sold under repurchase agreements	6,089	9,498
FHLB advances	100,000	70,000
Subordinated notes, net	6,893	6,877
Fair Value, Inputs, Level 1
Financial Assets:
Cash and due from banks	7,685	9,396
Interest-earning deposits	18,981	41,971
Federal funds sold	625	6,961
Financial Liabilities:
Noninterest-bearing liabilities	114,122	103,037
Savings and other interest-bearing deposits	359,400	299,820
Securities sold under repurchase agreements	6,089	9,498
Fair Value, Inputs, Level 2
Financial Assets:
Certificates of deposit	3,746	3,224
Restricted securities		5,787
Loans held for sale	368	1,651
Accrued interest receivable	3,172	3,194
Financial Liabilities:
FHLB advances	99,727	70,486
Fair Value, Inputs, Level 3
Financial Assets:
Restricted securities	7,600
Loans receivable, net	877,114	774,009
Financial Liabilities:
Time deposits	369,347	356,450
Subordinated notes, net	7,046	7,000
Carrying Value
Financial Assets:
Cash and due from banks	7,685	9,396
Interest-earning deposits	18,981	41,971
Certificates of deposit	3,746	3,224
Federal funds sold	625	6,961
Restricted securities	7,600	5,787
Loans receivable, net	894,191	758,726
Loans held for sale	368	1,651
Accrued interest receivable	3,172	3,194
Financial Liabilities:
Noninterest-bearing liabilities	114,122	103,037
Savings and other interest-bearing deposits	359,400	299,820
Time deposits	368,670	358,989
Securities sold under repurchase agreements	6,089	9,498
FHLB advances	100,000	70,000
Subordinated notes, net	6,893	6,877
Fair Value
Financial Assets:
Cash and due from banks	7,685	9,396
Interest-earning deposits	18,981	41,971
Certificates of deposit	3,746	3,224
Federal funds sold	625	6,961
Restricted securities	7,600	5,787
Loans receivable, net	877,114	774,009
Loans held for sale	368	1,651
Accrued interest receivable	3,172	3,194
Financial Liabilities:
Noninterest-bearing liabilities	114,122	103,037
Savings and other interest-bearing deposits	359,400	299,820
Time deposits	369,347	356,450
Securities sold under repurchase agreements	6,089	9,498
FHLB advances	99,727	70,486
Subordinated notes, net	$ 7,046	$ 7,000