Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
AOCI Attributable, Net of Tax [Roll Forward]
Beginning balance	$ 113,338	$ 105,216	$ 109,240	$ 101,352	$ 101,352
Adjusted beginning balance							$ 101,352
Current period comprehensive income (loss)	(513)	(160)	(979)	(234)
Ending balance	115,210	107,046	115,210	107,046	109,240
Net unrealized loss on available for sale securities
AOCI Attributable, Net of Tax [Roll Forward]
Beginning balance			(372)	(248)	(248)
Reclassifications upon adoption of ASU 2016-01							184
Adjusted beginning balance						$ (372)	(64)
Current period comprehensive income (loss)			223		(308)
Ending balance	(149)		(149)		(372)
Unfunded status of the supplemental retirement plans
AOCI Attributable, Net of Tax [Roll Forward]
Beginning balance			(459)	(462)	(462)
Adjusted beginning balance						(459)	(462)
Current period comprehensive income (loss)			30		3
Ending balance	(429)		(429)		(459)
Net unrealized gain on junior subordinated debentures
AOCI Attributable, Net of Tax [Roll Forward]
Beginning balance			1,505	0	0
Reclassifications upon adoption of ASU 2016-01							1,482
Adjusted beginning balance						$ 1,505	1,482
Current period comprehensive income (loss)			(1,232)		23
Ending balance	273		273		1,505
Accumulated other comprehensive (loss) income
AOCI Attributable, Net of Tax [Roll Forward]
Beginning balance	208	882	674	(710)	(710)
Adjusted beginning balance							$ 956
Ending balance	$ (305)	$ 722	$ (305)	$ 722	$ 674