XML 68 R58.htm IDEA: XBRL DOCUMENT
v3.20.2

Accumulated Other Comprehensive Income (Loss) (Changes in AOCI by component) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning Balance | $ 8,367 | $ 767 | $ 1,971 | $ (7,685)
OCI before reclassifications | 46 | (1,687) | (8,159) | (12,309)
Amounts reclassified from AOCI | 0 | (6) | (71) | (6)
Other Comprehensive Income (Loss), before Tax | (46) | 1,681 | 8,088 | 12,303
Tax effect | 54 | (302) | (1,684) | (2,472)
Unrealized gains (losses), net of tax | 8 | 1,379 | 6,404 | 9,831
Ending Balance | 8,375 | 2,146 | 8,375 | 2,146
Unrealized Holding Gains (Losses) on AFS Securities [Member] |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning Balance | 11,139 | 3,417 | 4,612 | (5,200)
OCI before reclassifications | 66 | (1,724) | (8,304) | (12,554)
Amounts reclassified from AOCI | 0 | (6) | (71) | (6)
Other Comprehensive Income (Loss), before Tax | (66) | 1,718 | 8,233 | 12,548
Tax effect | 58 | (310) | (1,714) | (2,523)
Unrealized gains (losses), net of tax | (8) | 1,408 | 6,519 | 10,025
Ending Balance | 11,131 | 4,825 | 11,131 | 4,825
Defined Benefit Pension Plan [Member] |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning Balance | (2,695) | (2,741) | (2,695) | (2,741)
OCI before reclassifications | 0 | 0 | 0 | 0
Amounts reclassified from AOCI | 0 | 0 | 0 | 0
Other Comprehensive Income (Loss), before Tax | 0 | 0 | 0 | 0
Tax effect |  | 0 | 0 | 0
Unrealized gains (losses), net of tax | 0 | 0 | 0 | 0
Ending Balance | (2,695) | (2,741) | (2,695) | (2,741)
Gain (Loss) on Derivative Instruments [Member] |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning Balance | (77) | 91 | 54 | 256
OCI before reclassifications | (20) | 37 | 145 | 245
Amounts reclassified from AOCI | 0 | 0 | 0 | 0
Other Comprehensive Income (Loss), before Tax | 20 | (37) | (145) | (245)
Tax effect | (4) | 8 | 30 | 51
Unrealized gains (losses), net of tax | 16 | (29) | (115) | (194)
Ending Balance | (61) | 62 | (61) | 62
Auction Rate Money Market Preferred Stocks [Member] | Unrealized Holding Gains (Losses) on AFS Securities [Member] |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Unrealized gains (losses), net of tax | $ 215 | $ 240 | $ 75 | $ 535

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_AOCIAttributableToParentNetOfTaxRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580 + Details
Name: | us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount before tax, after reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33775-111570 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=118951672&loc=d3e1436-108581 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of tax expense (benefit) allocated to other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 11 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e39076-109324 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e640-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before tax of reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17B -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL34724394-108580 + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_GainLossOnDerivativeInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=isba_AuctionRateMoneyMarketPreferredStocksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |