Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018	Jan. 01, 2019	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 229,473	$ 209,840	$ 222,542	[1]	$ 208,717
Net unrealized gains (losses) on securities available for sale, net of tax	3,186	(1,121)	6,266		(3,994)
Reclassification adjustment for realized gains on securities, net of tax	(105)		(108)		(6)
Change in accounting for late charges						$ 0
Unrealized losses on cash flow hedges	(843)
Ending Balance	311,917	213,348	311,917		213,348
Net unrealized gains (losses) on securities available for sale, tax	920	(325)	1,809		(1,186)
Reclassification adjustment for realized gains on securities, tax	(31)	0	(32)		(2)
Tax effect	(243)	(53)	(405)		(53)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax		(184)
Net Unrealized Gains (Losses) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(896)	(4,325)	(3,973)		(796)
Net unrealized gains (losses) on securities available for sale, net of tax	3,186	(1,121)	6,266		(3,994)
Reclassification adjustment for realized gains on securities, net of tax	(105)		(108)		(6)
Change in accounting for late charges							$ (650)
Ending Balance	2,185	(5,446)	2,185		(5,446)
Unrealized Losses on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		0	(624)
Unrealized losses on cash flow hedges			(1,406)
Ending Balance	(2,030)	(184)	(2,030)		(184)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax		(184)			(184)
Unrealized Losses on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(1,187)
Unrealized losses on cash flow hedges	(843)
Ending Balance	(2,030)		(2,030)
Adjustments Related to Pension Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(1,238)	(2,280)	(1,238)		(2,280)
Ending Balance	(1,238)	(2,280)	(1,238)		(2,280)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(3,321)	(6,605)	(5,835)		(3,076)
Change in accounting for late charges							$ (650)
Unrealized losses on cash flow hedges			(1,406)
Ending Balance	$ (1,083)	$ (7,910)	$ (1,083)		(7,910)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax					$ (184)

[1] Derived from audited consolidated financial statements.