Note 5 - Investment Securities - Obligations of States, Municipalities and Political Subdivisions (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost	$ 44,737	$ 38,867
Fair Value	44,601	38,988
General Obligation [Member]
Amortized Cost	40,468	32,766
Fair Value	40,298	32,858
General Obligation [Member] | School [Member] | Pennsylvania Municipalities [Member]
Amortized Cost	27,319	29,671
Fair Value	27,143	29,755
General Obligation [Member] | School [Member] | Other State Municipalities [Member]
Amortized Cost	4,296
Fair Value	4,277
General Obligation [Member] | Public Improvement [Member] | Pennsylvania Municipalities [Member]
Amortized Cost	3,532	3,095
Fair Value	3,508	3,103
General Obligation [Member] | Public Improvement [Member] | Other State Municipalities [Member]
Amortized Cost	5,321
Fair Value	5,370
Special Revenue [Member]
Amortized Cost	4,269	6,101
Fair Value	4,303	6,130
Special Revenue [Member] | School [Member] | Other State Municipalities [Member]
Amortized Cost		2,653
Fair Value		2,659
Special Revenue [Member] | Public Improvement [Member] | Other State Municipalities [Member]
Amortized Cost	330	977
Fair Value	342	992
Special Revenue [Member] | Other [Member] | Pennsylvania Municipalities [Member]
Amortized Cost	2,144	2,221
Fair Value	2,133	2,227
Special Revenue [Member] | Other [Member] | Other State Municipalities [Member]
Amortized Cost	1,795
Fair Value	1,828
Special Revenue [Member] | Water and Sewer [Member] | Other State Municipalities [Member]
Amortized Cost		250
Fair Value		$ 252