Portfolio Loans - Narrative (Details) $ in Millions	Dec. 31, 2019 USD ($)
Unadvanced Commitment on Impaired Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated losses attributable to unadvanced commitments on impaired loans	$ 0.4

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration