Parent Only Condensed Financial Statements - Condensed Cash Flow Statement (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 9,285	$ 8,952	$ 8,829	$ 8,895	$ 7,904	$ 7,071	$ 7,992	$ 6,710	$ 35,961	$ 29,677	$ 19,539
Adjustments to reconcile net income to net cash provided by operating activities:
Loss (gain) on sales of securities									198	(2)	(500)
Increase (decrease) in other assets									(9,224)	(6,106)	10,402
(Decrease) increase in other liabilities									9,662	(5,420)	4,100
Net cash provided by operating activities									46,737	30,446	40,679
Cash flows from investing activities:
Net cash used in investing activities									(53,290)	(188,188)	(51,673)
Cash flows from financing activities:
Stock options exercised									1,088	1,131	764
Repurchases of common stock									(2,544)	0	0
Net cash provided by financing activities									12,498	161,737	(39,311)
Cash and cash equivalents, beginning of year				74,132				70,137	74,132	70,137	120,442
Cash and cash equivalents, end of year	80,077				74,132				80,077	74,132	70,137
Parent [Member]
Cash flows from operating activities:
Net income									35,961	29,677	19,539
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed net loss of subsidiary									(20,869)	(23,826)	(4,260)
Loss (gain) on sales of securities									0	0	(918)
Increase (decrease) in other assets									178	183	170
(Decrease) increase in other liabilities									(2)	28	(757)
Net cash provided by operating activities									15,268	6,062	13,774
Cash flows from investing activities:
Sales of securities									0	0	1,480
Cash paid from acquisitions, net									0	(6)	(7,061)
Net cash used in investing activities									0	(6)	(5,581)
Cash flows from financing activities:
Change in other borrowings									0	0	0
Stock options exercised									1,088	1,131	764
Repurchases of common stock									(2,544)	0	0
Dividends paid									(11,332)	(9,757)	(7,935)
Net cash provided by financing activities									(12,788)	(8,626)	(7,171)
(Decrease) increase in cash and due from banks									2,480	(2,570)	1,022
Cash and cash equivalents, beginning of year				$ 2,338				$ 4,908	2,338	4,908	3,886
Cash and cash equivalents, end of year	$ 4,818				$ 2,338				$ 4,818	$ 2,338	$ 4,908