Financing receivable loan modifications value due to CARES Act, not considered troubled debt restructuring.

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Number of financing receivable loan modifications due to CARES Act, not considered troubled debt restructuring.

+ References

No definition available.

+ Details

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Namespace Prefix:	alrs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Typical loan deferral period under the CARES Act.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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Balance Type:
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- Details

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- Details

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Loans and Allowance for Loan Losses - Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 loan	Jun. 30, 2021 USD ($) loan
Troubled debt restructuring
Number of loans modified as a troubled debt restructuring \| loan	3	0
Number of loan modifications not considered TDRs, in connection with CARES Act \| loan	584		584
Loan modifications not considered TDRS, in connection with CARES Act \| $	$ 154,500		$ 154,500
Maximum
Troubled debt restructuring
Typical loan deferral period under the CARES Act			90 days
Extending amortization period
Troubled debt restructuring
Carrying value of restructured loan \| $			$ 795
Second Deferral
Troubled debt restructuring
Number of loan modifications not considered TDRs, in connection with CARES Act \| loan	12		12
Loan modifications not considered TDRS, in connection with CARES Act \| $	$ 5,300		$ 5,300
First Deferral
Troubled debt restructuring
Number of loan modifications not considered TDRs, in connection with CARES Act \| loan	4		4
Loan modifications not considered TDRS, in connection with CARES Act \| $	$ 653		$ 653