XML 53 R43.htm IDEA: XBRL DOCUMENT v3.20.2

Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,303,308	$ 1,186,570
Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	821,102	700,941
Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	499,386	510,153
Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	246,700	155,265
Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	75,016	35,523
Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	102,263	116,920
Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	71,939	80,027
Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	30,324	36,893
Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	923,365	817,861
1 - Excellent [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	390
1 - Excellent [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
1 - Excellent [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	390
1 - Excellent [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
1 - Excellent [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
1 - Excellent [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
1 - Excellent [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
1 - Excellent [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	390
2 - High quality [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	19,756	11,426
2 - High quality [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,909	2,582
2 - High quality [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	16,847	8,844
2 - High quality [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
2 - High quality [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	621	1,551
2 - High quality [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	608	1,452
2 - High quality [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	13	99
2 - High quality [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	20,377	12,977
3 - High satisfactory [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	226,959	188,118
3 - High satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	89,929	109,737
3 - High satisfactory [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	62,014	42,858
3 - High satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	75,016	35,523
3 - High satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	21,262	23,534
3 - High satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	16,382	16,765
3 - High satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,880	6,769
3 - High satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	248,221	211,652
4 - Low satisfactory [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	533,994	472,045
4 - Low satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	381,347	377,198
4 - Low satisfactory [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	152,647	94,847
4 - Low satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
4 - Low satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	50,940	63,659
4 - Low satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	32,794	42,798
4 - Low satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	18,146	20,861
4 - Low satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	584,934	535,704
5 - Special mention [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	24,844	18,842
5 - Special mention [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	18,127	15,372
5 - Special mention [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,717	3,470
5 - Special mention [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
5 - Special mention [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	16,687	10,919
5 - Special mention [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	13,140	7,165
5 - Special mention [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,547	3,754
5 - Special mention [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	41,531	29,761
6 - Substandard [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	14,185	8,499
6 - Substandard [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	7,047	4,874
6 - Substandard [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	7,138	3,625
6 - Substandard [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
6 - Substandard [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	9,215	12,972
6 - Substandard [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,914	9,136
6 - Substandard [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,301	3,836
6 - Substandard [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	23,400	21,471
7 - Vulnerable [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,364	1,621
7 - Vulnerable [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	27	390
7 - Vulnerable [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,337	1,231
7 - Vulnerable [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
7 - Vulnerable [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,348	4,285
7 - Vulnerable [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,911	2,711
7 - Vulnerable [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	437	1,574
7 - Vulnerable [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,712	5,906
8 - Doubtful [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
8 - Doubtful [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	190	0
8 - Doubtful [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	190	0
8 - Doubtful [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	190	0
Loss [Member] | Total commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Commercial other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Total agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Agricultural real estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Agricultural other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Loss [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 0	$ 0

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, before allowance for credit loss, of financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919230-210447

+ Details

Name:	us-gaap_NotesReceivableGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_CommercialOtherPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_CommercialAdvancestoMortgageBrokersSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_AgriculturalPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_AgriculturalRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_AgriculturalOtherPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=isba_CommercialAndAgriculturalPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_ExcellentRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_HighQualityRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_HighSatisfactoryRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_LowSatisfactoryRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_VulnerableRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=isba_LossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: