Pension Benefits (Narrative) (Details) (Pension Plans, Defined Benefit [Member])	3 Months Ended
Mar. 31, 2015
Pension Plans, Defined Benefit [Member]
Pension Benefits [Line Items]
Minimum number of annual hours	1,000
Vesting term	5 years
Maximum percent of plan assets comprised of AmeriServ Financial, Inc. common stock	10.00%

Defined Benefit Plan, Maximum Percent Of Assets Comprised Of Entity Common Stock.

No definition available.

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Namespace Prefix:	asrv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant