Parent-only Financial Statements, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities [Abstract]
Net income	$ 5,561	$ 6,710	$ 6,379	$ 6,350	$ 4,567	$ 5,950	$ 6,689	$ 6,583	$ 25,000	$ 23,789	$ 16,817
Items not requiring (providing) cash [Abstract]
Stock-based compensation expense									154	0	0
Changes in [Abstract]
Net cash provided by operating activities									27,001	25,877	19,357
Financing Activities [Abstract]
Repayment of Borrowed Funds									(5,600)	(800)	(800)
Cash dividends paid									(56,155)	(9,749)	(6,995)
Common stock issued, net of offering costs									50,154	0	0
Net cash provided by financing activities									38,608	65,726	32,991
Increase (Decrease) in Cash and Due from Banks									28,036	25,810	8,068
Cash and Due from Banks, Beginning of Year				100,054				74,244	100,054	74,244	66,176
Cash and Due from Banks, End of Year	128,090				100,054				128,090	100,054	74,244
Supplemental Disclosure of Cash Flows Information [Abstract]
Interest paid									7,304	4,739	3,303
Parent Company [Member]
Operating Activities [Abstract]
Net income									25,000	23,789	16,817
Items not requiring (providing) cash [Abstract]
Equity in undistributed net income of bank subsidiary									(13,521)	(13,262)	(9,030)
Stock-based compensation expense									154	0	0
Changes in [Abstract]
Other assets									(39)	0	0
Other liabilities									238	(2)	(2)
Net cash provided by operating activities									11,832	10,525	7,785
Financing Activities [Abstract]
Repayment of Borrowed Funds									(5,600)	(800)	(800)
Cash dividends paid									(56,155)	(9,749)	(6,995)
Common stock issued, net of offering costs									50,154	0	0
Net cash provided by financing activities									(11,601)	(10,549)	(7,795)
Increase (Decrease) in Cash and Due from Banks									231	(24)	(10)
Cash and Due from Banks, Beginning of Year				$ 64				$ 88	64	88	98
Cash and Due from Banks, End of Year	$ 295				$ 64				295	64	88
Supplemental Disclosure of Cash Flows Information [Abstract]
Interest paid									$ (175)	$ 239	$ 265