Loans and Other Real Estate - Impaired Loans with and without Specific Allowances (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Recorded Investment in Impaired Loans	$ 32,355	$ 22,124
Contractual Unpaid Principal Balance	33,324	22,776
Specific Allowance	271	352
Average Investment in Impaired Loans	28,153	18,342
Interest Income Recognized	199	426
Commercial, secured by real estate
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	24,245	12,478
Loans with related allowance, Recorded Investment in Impaired Loans	3,222	3,470
Recorded Investment in Impaired Loans	27,467	15,948
Loans without related allowance, Contractual Unpaid Principal Balance	24,541	12,630
Loans with related allowance, Contractual Unpaid Principal Balance	3,472	3,706
Contractual Unpaid Principal Balance	28,013	16,336
Specific Allowance	187	228
Loans without related allowance, Average Investment in Impaired Loans	19,502	10,386
Loans with related allowance, Average Investment in Impaired Loans	3,308	4,554
Average Investment in Impaired Loans	22,810	14,940
Loans without related allowance, Interest Income Recognized	79	164
Loans with related allowance, Interest Income Recognized	75	190
Interest Income Recognized	154	354
Commercial, industrial and other
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	1,308	1,391
Loans with related allowance, Recorded Investment in Impaired Loans	102	113
Recorded Investment in Impaired Loans	1,410	1,504
Loans without related allowance, Contractual Unpaid Principal Balance	1,313	1,381
Loans with related allowance, Contractual Unpaid Principal Balance	101	113
Contractual Unpaid Principal Balance	1,414	1,494
Specific Allowance	5	5
Loans without related allowance, Average Investment in Impaired Loans	1,336	1,334
Loans with related allowance, Average Investment in Impaired Loans	101	113
Average Investment in Impaired Loans	1,437	1,447
Loans without related allowance, Interest Income Recognized	8	16
Loans with related allowance, Interest Income Recognized	3	6
Interest Income Recognized	11	22
Equipment finance
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	0	0
Loans with related allowance, Recorded Investment in Impaired Loans	17	23
Recorded Investment in Impaired Loans	17	23
Loans without related allowance, Contractual Unpaid Principal Balance	0	0
Loans with related allowance, Contractual Unpaid Principal Balance	17	23
Contractual Unpaid Principal Balance	17	23
Specific Allowance	7	10
Loans without related allowance, Average Investment in Impaired Loans	0	0
Loans with related allowance, Average Investment in Impaired Loans	19	21
Average Investment in Impaired Loans	19	21
Loans without related allowance, Interest Income Recognized	0	0
Loans with related allowance, Interest Income Recognized	0	0
Interest Income Recognized	0	0
Real estate - residential mortgage
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	1,516	803
Loans with related allowance, Recorded Investment in Impaired Loans	644	1,512
Recorded Investment in Impaired Loans	2,160	2,315
Loans without related allowance, Contractual Unpaid Principal Balance	1,647	815
Loans with related allowance, Contractual Unpaid Principal Balance	827	1,682
Contractual Unpaid Principal Balance	2,474	2,497
Specific Allowance	67	104
Loans without related allowance, Average Investment in Impaired Loans	1,577	233
Loans with related allowance, Average Investment in Impaired Loans	651	926
Average Investment in Impaired Loans	2,228	1,159
Loans without related allowance, Interest Income Recognized	0	0
Loans with related allowance, Interest Income Recognized	9	19
Interest Income Recognized	9	19
Real estate - construction
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	694	1,663
Loans with related allowance, Recorded Investment in Impaired Loans	0	0
Recorded Investment in Impaired Loans	694	1,663
Loans without related allowance, Contractual Unpaid Principal Balance	694	1,661
Loans with related allowance, Contractual Unpaid Principal Balance	0	0
Contractual Unpaid Principal Balance	694	1,661
Specific Allowance	0	0
Loans without related allowance, Average Investment in Impaired Loans	1,043	82
Loans with related allowance, Average Investment in Impaired Loans	0	0
Average Investment in Impaired Loans	1,043	82
Loans without related allowance, Interest Income Recognized	10	2
Loans with related allowance, Interest Income Recognized	0	0
Interest Income Recognized	10	2
Home equity and consumer
Financing Receivable, Impaired [Line Items]
Loans without related allowance, Recorded Investment in Impaired Loans	0	0
Loans with related allowance, Recorded Investment in Impaired Loans	607	671
Recorded Investment in Impaired Loans	607	671
Loans without related allowance, Contractual Unpaid Principal Balance	0	0
Loans with related allowance, Contractual Unpaid Principal Balance	712	765
Contractual Unpaid Principal Balance	712	765
Specific Allowance	5	5
Loans without related allowance, Average Investment in Impaired Loans	0	0
Loans with related allowance, Average Investment in Impaired Loans	616	693
Average Investment in Impaired Loans	616	693
Loans without related allowance, Interest Income Recognized	0	0
Loans with related allowance, Interest Income Recognized	15	29
Interest Income Recognized	$ 15	$ 29

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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