Parent Company Financial Information, Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statements of Cash Flows [Abstract]
Net income	$ 12,551	$ 8,748	$ 8,051
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Stock plan accruals	424	378	286
Net cash provided by operating activities	15,679	16,095	9,706
Cash flows from financing activities [Abstract]
Common stock issued	91	78	61
Stock options exercised	0	0	21
Net cash provided by financing activities	19,953	41,112	115,655
Net decrease in cash and cash equivalents	(36,860)	(6,751)	(41,154)
Cash and cash equivalents at beginning of year	152,892	159,643	200,797
Cash and cash equivalents at end of year	116,032	152,892	159,643
Parent Company [Member]
Statements of Cash Flows [Abstract]
Net income	12,551	8,748	8,051
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Stock plan accruals	424	378	286
Equity in undistributed earnings of subsidiary	(12,711)	(8,880)	(8,166)
Net cash provided by operating activities	264	246	171
Cash flows from financing activities [Abstract]
Common stock issued	91	78	61
Stock options exercised	0	0	25
Cash in lieu of fractional shares	(10)	(10)	(5)
Net cash provided by financing activities	81	68	81
Net decrease in cash and cash equivalents	345	314	252
Cash and cash equivalents at beginning of year	2,810	2,496	2,244
Cash and cash equivalents at end of year	$ 3,155	$ 2,810	$ 2,496