Investment Securities - Securities in Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule Of Investments [Line Items]
Available-for-sale, less than 12 months, fair value	$ 20,686	$ 10,836
Available-for-sale, less than 12 months, unrealized losses	(145)	(92)
Available-for-sale, 12 months or more, fair value	43,855	107,357
Available-for-sale, 12 months or more, unrealized losses	(660)	(3,251)
Held-to-maturity, less than 12 months, fair value	2,925	770
Held-to-maturity, less than 12 months, unrealized losses	(17)
Held-to-maturity, 12 months or more, fair value	13,384	20,082
Held-to-maturity, 12 months or more, unrealized losses	(95)	(610)
Residential Mortgage Backed Securities [Member]
Schedule Of Investments [Line Items]
Available-for-sale, less than 12 months, fair value	16,466	9,417
Available-for-sale, less than 12 months, unrealized losses	(135)	(87)
Available-for-sale, 12 months or more, fair value	11,030	53,507
Available-for-sale, 12 months or more, unrealized losses	(185)	(1,430)
Commercial Mortgage Backed Securities [Member]
Schedule Of Investments [Line Items]
Available-for-sale, less than 12 months, fair value	4,140	461
Available-for-sale, less than 12 months, unrealized losses	(10)	(3)
Available-for-sale, 12 months or more, fair value	32,825	53,430
Available-for-sale, 12 months or more, unrealized losses	(475)	(1,819)
Held-to-maturity, less than 12 months, fair value	1,522
Held-to-maturity, less than 12 months, unrealized losses	(9)
Held-to-maturity, 12 months or more, fair value	7,902	11,367
Held-to-maturity, 12 months or more, unrealized losses	(74)	(349)
US Treasury Securities [Member]
Schedule Of Investments [Line Items]
Available-for-sale, less than 12 months, fair value	80	79
US Government Agencies Debt Securities [Member]
Schedule Of Investments [Line Items]
Held-to-maturity, less than 12 months, fair value	1,403
Held-to-maturity, less than 12 months, unrealized losses	(8)
Held-to-maturity, 12 months or more, fair value	4,979	7,782
Held-to-maturity, 12 months or more, unrealized losses	(21)	(244)
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Investments [Line Items]
Available-for-sale, less than 12 months, fair value		879
Available-for-sale, less than 12 months, unrealized losses		(2)
Available-for-sale, 12 months or more, fair value		420
Available-for-sale, 12 months or more, unrealized losses		(2)
Held-to-maturity, less than 12 months, fair value		770
Held-to-maturity, 12 months or more, fair value	$ 503	933
Held-to-maturity, 12 months or more, unrealized losses		$ (17)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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