Long-Term Debt and FHLB Stock (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Long-Term Debt And Federal Home Loan Bank [Line Items]
Advances from Federal Home Loan Banks	$ 59,016	$ 59,016		$ 66,304
Funding received		11,923	$ (4,369)
Federal Reserve Bank borrowings	12,080	12,080
Atlantic Community Bankers Bank
Long-Term Debt And Federal Home Loan Bank [Line Items]
Line of credit facility, maximum amount outstanding during period					$ 5,000
Zions Bank
Long-Term Debt And Federal Home Loan Bank [Line Items]
Line of credit, maximum borrowing capacity	$ 10,000	10,000		10,000
Line of credit facility, maximum amount outstanding during period		$ 0		$ 0
Paycheck Protection Program
Long-Term Debt And Federal Home Loan Bank [Line Items]
Interest rate	0.35%	0.35%
Percentage of Principal Funding		100.00%
Funding received	$ 70,100
Federal Reserve Bank borrowings	$ 12,100	$ 12,100
Subordinated Debt.
Long-Term Debt And Federal Home Loan Bank [Line Items]
Interest rate, variable rate basis		3-month LIBOR
Interest LIBOR rate		2.00%
Interest rate	2.30%	2.30%		3.91%
Subordinated debt securities	$ 5,155	$ 5,155
Stated maturity date		May 23, 2035
Subordinated Debt. | RSB Capital Trust I
Long-Term Debt And Federal Home Loan Bank [Line Items]
Interest rate, variable rate basis		3-month LIBOR
Interest LIBOR rate		2.00%
Trust term	30 years	30 years
Federal Home Loan Bank of New York ("FHLBNY")
Long-Term Debt And Federal Home Loan Bank [Line Items]
Line of credit, maximum borrowing capacity	$ 564,068	$ 564,068		$ 486,906
Advances from Federal Home Loan Banks	59,016	59,016
Amount of pledged assets	180,161	180,161		168,230
Impairment Related To Federal Home Loan Stock	$ 0	$ 0		$ 0