Parent Company Only Financial Statements Condensed statements of cash flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net income	$ 47,943	$ 36,600	$ 26,684
Depreciation, amortization and accretion, net	10,842	7,881	8,134
Increase in other assets	(4,680)	(4,266)	668
Increase (decrease) in other liabilities	3,282	(7,846)	666
Net cash provided by operating activities	62,828	42,175	46,154
Cash Acquired from Acquisition	0	56,389	0
Net cash used in investing activities	(32,072)	(10,961)	(55,962)
Repayment of short-term debt	0	0	(4,000)
Repayments of Long-term Debt	(7,724)	(10,313)	(3,750)
Proceeds from issuance of common stock	655	36,645	4,399
Payments for Repurchase of Common Stock	(1,293)	(138)	(797)
Direct expenses related to capital transactions	0	(2,309)	(216)
Dividends paid on common stock	(11,863)	(8,792)	(7,228)
Net cash provided by (used in) financing activities	(87,076)	21,307	(77,215)
Increase (decrease) in cash	(56,320)	52,521	(87,023)
Cash and cash equivalents at beginning of period	141,400	88,879	175,902
Cash and cash equivalents at end of period	85,080	141,400	88,879
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	47,943	36,600	26,684
Depreciation, amortization and accretion, net	125	90	82
Dividends from subsidiaries	38,688	21,694	18,925
Equity in undistributed earnings of subsidiaries	(12,479)	(18,885)	(9,570)
Increase in other assets	(39,042)	(1,645)	(19,348)
Increase (decrease) in other liabilities	(17,104)	79	733
Net cash provided by operating activities	18,131	37,933	17,506
Payments to Acquire Additional Interest in Subsidiaries	(343)	(13,430)	0
Cash Acquired from Acquisition	310	(29,321)	0
Net cash used in investing activities	(33)	(42,751)	0
Repayment of short-term debt	0	0	(4,000)
Repayments of Long-term Debt	(10,310)	(10,313)	(3,750)
Proceeds from issuance of common stock	589	36,645	4,399
Payments for Repurchase of Common Stock	(1,293)	(138)	(797)
Direct expenses related to capital transactions	0	(2,309)	(216)
Dividends paid on common stock	(11,863)	(8,792)	(7,228)
Net cash provided by (used in) financing activities	(22,877)	15,093	(11,592)
Increase (decrease) in cash	(4,779)	10,275	5,914
Cash and cash equivalents at beginning of period	18,571	8,296	2,382
Cash and cash equivalents at end of period	$ 13,792	$ 18,571	$ 8,296