Components of Salisbury's net deferred tax assets (Details) - SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Valuation Allowance [Line Items]
Allowance for loan losses	$ 3,170	$ 3,355
Interest on non-performing loans	157	214
Accrued deferred compensation	488	517
Post-retirement benefits	11	11
Mark-to-market purchase accounting adjustments	17
Loss on equity securities	4
Restricted stock awards	361	196
Deferred loan costs, net		90
Other	183	98
Gross deferred tax assets	4,391	4,481
Deferred loan fees, net	(69)
Mark-to-market purchase accounting adjustments		(8)
Goodwill and core deposit intangible asset	(615)	(590)
Accelerated depreciation	(681)	(522)
Gain on equity securities		(2)
Prepaid expenses	(32)
Gain on disposal	(5)
Mortgage servicing rights	(169)	(150)
Net unrealized holding gains on available-for-sale securities	(232)	(797)
Gross deferred tax liabilities	(1,803)	(2,069)
Net deferred tax asset	$ 2,588	$ 2,412