XML 86 R74.htm IDEA: XBRL DOCUMENT v3.20.4

Borrowed Funds (Borrowed funds obligations) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule of Debt [Line Items]
Borrowed funds	$ 158,747	$ 275,999
Borrowed funds, Rate	1.01%	2.07%
Securities Sold under Agreements to Repurchase [Member]
Schedule of Debt [Line Items]
Borrowed funds	$ 68,747	$ 30,999
Borrowed funds, Rate	0.13%	0.09%
Federal Home Loan Bank Advances [Member]
Schedule of Debt [Line Items]
Borrowed funds	$ 90,000	$ 245,000
Borrowed funds, Rate	1.68%	2.32%

X

- Definition

[Line Items] for Schedule of Debt [Table]

+ References

No definition available.

+ Details

Name:	isba_ScheduleofDebtLineItems
Namespace Prefix:	isba_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtLongtermAndShorttermCombinedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_FederalHomeLoanBankAdvancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: