Fair Value - Securities Available for Sale Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Residential & multi-family mortgage
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1, 2020	$ 2,795
Purchases	0
Total gains or (losses):
Included in other comprehensive income (loss)	0
Transfers out of Level 3	(2,795)
Balance, September 30, 2020	0
State & political subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1, 2020	0
Purchases	422
Total gains or (losses):
Included in other comprehensive income (loss)	0
Transfers out of Level 3	0
Balance, September 30, 2020	$ 422