Accumulated Other Comprehensive Loss - Schedule of Reclassifications out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassifications out of accumulated other comprehensive income
Income tax provision	$ (812)	$ (589)
Salaries and employee benefits	(5,501)	(5,048)
NET INCOME ATTRIBUTABLE TO PENNS WOODS BANCORP, INC.	3,944	3,209
Amount Reclassified from Accumulated Other Comprehensive Loss | Net Unrealized Gain (Loss) on Available for Sale Securities
Reclassifications out of accumulated other comprehensive income
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	13	(9)
Income tax provision	(3)	3
NET INCOME ATTRIBUTABLE TO PENNS WOODS BANCORP, INC.	10	(6)
Amount Reclassified from Accumulated Other Comprehensive Loss | Defined Benefit Plan
Reclassifications out of accumulated other comprehensive income
Income tax provision	10	8
Salaries and employee benefits	(47)	(42)
NET INCOME ATTRIBUTABLE TO PENNS WOODS BANCORP, INC.	$ (37)	$ (34)