Derivative Hedging Instruments (Details) - Swap - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Derivative Financial Instruments, Liabilities
Derivative Hedging Instruments
Hedge Type	N/A	N/A
Aggregate notional amount	$ (63,143)	$ (64,509)
Weighted average rate received/(paid)	(5.99%)	(6.66%)
Repricing frequency	Monthly	Monthly
Increase (decrease) in interest income	$ (347)	$ (644)
Derivative Financial Instruments, Assets
Derivative Hedging Instruments
Hedge Type	N/A	N/A
Aggregate notional amount	$ 63,143	$ 64,509
Weighted average rate received/(paid)	5.99%	6.66%
Repricing frequency	Monthly	Monthly
Increase (decrease) in interest income	$ 347	$ 644

Description for repricing frequency of derivative instruments.

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

The percentage of interest received(Paid) during the period under Interest Rate swap transaction.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
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- Definition

This amount represents the increase (decrease) in interest income (not fair value) of interest rate swaps.

+ References

No definition available.

+ Details

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Namespace Prefix:	asrv_
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Balance Type:	debit
Period Type:	duration

- Definition

Nominal or face amount used to calculate payments on the derivative asset.

+ References

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+ Details

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Period Type:	instant

- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

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-Name Accounting Standards Codification
-Section 50
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
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+ Details

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- Definition

Indicates whether the entity pays a variable or fixed price on a price risk swap.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5

+ Details

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- Details

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- Details

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- Details

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