Segment and Related Information - Narrative (Details) - 12 months ended Dec. 31, 2019 |
segment |
banking_office |
subsidiary_bank |
office |
---|---|---|---|---|
Segment Reporting Information [Line Items] | ||||
Number of reportable business segments | segment | 3 | |||
Number of subsidiary banks (banking office) | 4 | 4 | ||
Ithaca, NY | ||||
Segment Reporting Information [Line Items] | ||||
Number of banking offices | 14 | |||
Genesee Valley Region | ||||
Segment Reporting Information [Line Items] | ||||
Number of banking offices | 16 | |||
Counties North of New York City | ||||
Segment Reporting Information [Line Items] | ||||
Number of banking offices | 14 | |||
Southeastern Pennsylvania | ||||
Segment Reporting Information [Line Items] | ||||
Number of banking offices | 20 | |||
Western New York | ||||
Segment Reporting Information [Line Items] | ||||
Nature of operations, number of offices | office | 5 |