Defined Benefit Retirement Plan (Components of Net Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 114	$ 112
Expected return on plan assets	(142)	(148)
Recognized net actuarial loss	62	61
Net periodic pension cost (income)	34	25
Amortization of net actuarial loss recognized in other comprehensive income	(62)	(61)
Total recognized in net periodic pension cost and other comprehensive income	(28)	$ (36)
FNBPA Bancorp, Inc. [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	53
Expected return on plan assets	(57)
Recognized net actuarial loss
Net periodic pension cost (income)	(4)
Amortization of net actuarial loss recognized in other comprehensive income
Total recognized in net periodic pension cost and other comprehensive income	$ (4)