Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2019 RetailBankingOffice
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of retail banking offices	33
HSB Insurance, Inc. [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Operations commenced date	Jun. 01, 2017
Ohio [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of retail banking offices	32
Pennsylvania [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of retail banking offices	1