Revenue from Contracts with Customers - Additional Information (Detail)	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Percentage of primary source of revenue	90.80%	90.70%

Contract with Customer, Percentage of Primary Source of Revenue

No definition available.

Name:	ccne_ContractwithCustomerPercentageofPrimarySourceofRevenue
Namespace Prefix:	ccne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration