XML 54 R44.htm IDEA: XBRL DOCUMENT v3.8.0.1

Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,093,002	$ 1,091,519
Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	643,636	634,759
Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	477,080	481,654
Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	148,582	141,024
Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	17,974	12,081
Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	122,330	128,269
Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	86,879	88,165
Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	35,451	40,104
Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	765,966	763,028
1 - Excellent [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	23	340
1 - Excellent [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	23	24
1 - Excellent [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	316
1 - Excellent [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	34	34
1 - Excellent [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	34	34
1 - Excellent [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	57	374
2 - High quality [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	20,356	20,664
2 - High quality [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,417	8,402
2 - High quality [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	14,939	12,262
2 - High quality [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
2 - High quality [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,597	3,933
2 - High quality [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,783	2,909
2 - High quality [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	814	1,024
2 - High quality [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	23,953	24,597
3 - High satisfactory [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	179,890	190,575
3 - High satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	117,378	131,826
3 - High satisfactory [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	44,538	46,668
3 - High satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	17,974	12,081
3 - High satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	26,568	29,939
3 - High satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	20,474	21,072
3 - High satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,094	8,867
3 - High satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	206,458	220,514
4 - Low satisfactory [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	422,008	401,757
4 - Low satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	337,859	326,166
4 - Low satisfactory [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	84,149	75,591
4 - Low satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
4 - Low satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	64,106	66,302
4 - Low satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	46,040	47,835
4 - Low satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	18,066	18,467
4 - Low satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	486,114	468,059
5 - Special mention [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	10,177	12,875
5 - Special mention [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	8,615	8,986
5 - Special mention [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,562	3,889
5 - Special mention [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
5 - Special mention [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	14,810	19,039
5 - Special mention [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	9,618	10,493
5 - Special mention [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,192	8,546
5 - Special mention [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	24,987	31,914
6 - Substandard [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	7,615	7,819
6 - Substandard [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,424	5,521
6 - Substandard [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,191	2,298
6 - Substandard [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
6 - Substandard [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	11,322	7,072
6 - Substandard [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,435	4,325
6 - Substandard [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,887	2,747
6 - Substandard [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	18,937	14,891
7 - Vulnerable [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,567	729
7 - Vulnerable [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,364	729
7 - Vulnerable [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,203	0
7 - Vulnerable [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
7 - Vulnerable [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,893	1,950
7 - Vulnerable [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,529	1,531
7 - Vulnerable [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	364	419
7 - Vulnerable [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,460	2,679
8 - Doubtful [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [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 representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ 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: